Here's the list of suppliers originally listed on CloudStore when it went live on 19 Feb 2012 for those who just want a simple list (from the XLS spreadsheet via G-Cloud blog):
@UK PLC
100 Percent IT Limited
2e2 UK Ltd
4C Strategies Ltd
5NINES Data Centres Limited
6four2 ltd
Adapt Services Limited
Agile Delivery Network
AIMES Grid Services
Align Partnership LLP
Alliantist Limited including subsidiary Achieve Mo
Alpine Resourcing Limited
AMEE Limited
Amethyst Risk Management Limited
Ancoris Ltd
Appsbroker Consulting Limited
apto solutions limited
Arcus Global ltd.
Atkins Limited
Atos IT Services UK Limited
Attenda Limited
Azeus Systems Limited
Backup Technology Limited
Bang Communications
Baycloud Systems Ltd
BearingPoint
BIP Solutions Ltd.
BJSS Ltd.
Blackburn IT Services t/a bbits
Bramble.cc Limited
BravoSolution UK Limited
British Telecommunications plc
BusinessWeb Software t/a Firmstep Ltd
Cable&Wireless UK
Cadence Partnership LLP
Capgemini UK plc
Capita Business Services Ltd
CarbonZero IT LLC
Cassidian Limited
Castrum Limited
CGI ISMC UK Ltd
Claranet
Clicks and Links Ltd
CLOUD CACHE AND ARCHIVE LIMTED
Cloud Technology Solutions Ltd
Cloud Trade Technologies Limited
CloudLock Inc.
Cloudreach Limited
Cohesive Flexible Technologies Corporation
Colt Technology Services
Commercial technology Limited T/A Refractiv
Compulete Projects Limited
Computacenter (UK) Ltd
Connect Assist Limited
Consilium Technologies Ltd
Content Guru Ltd
Cordys Ltd
Core Technology Systems (UK) Limited trading as CO
Cornerstone OnDemand Inc.
CSC Computer Sciences Limited
Daemon Directory Systems Ltd.
Datatank Ltd
Delib
Delib
Dell Corporation Limited
Dot Net Solutions
Easylink Service International Limited
E-Box Ltd
Ecometrica Limited
Eduserv
Egress Software Technologies Ltd
ElasticHosts Ltd
eLINIA Web Services Ltd
emapsite.com Limited
EMC COMPUTER SYSTEMS (U.K.) LIMITED
Emergn Limited
enCircle Solutions Ltd.
Entity Group Limited
Equiniti ICS Ltd
ERS Consultancy Ltd
ESRI (UK) Limited
Esteem Systems Ltd
Eximium Ltd
FCO Services
Fincore Ltd
Fivium Limited
Flexible Computing Ltd
FlyingBinary Ltd
Foden Grealy Limited
Fordway Solutions Ltd
FreeVision Ltd
Fubra Limited
Fujitsu Services Limited
Funnelback UK Ltd
Future Route Limited
GCrypt Limited
Global Crossing Communications UK
Google Ireland Limited
Gordano Ltd
GovDelivery Inc
Govtech Solutions Limited
Grove Information Systems Limited
Health Analytics Ltd
Helpful Technology Ltd
Henley Software Limited
HighQ Solutions Limited
HP Ltd UK
HTK Limited
i2N ltd
IBM United Kingdom Limited
iCasework Limited
Iken Business Limited
Information Management Group Ltd
Informed Solutions Ltd
INOVEM Limited
Insight Direct (UK) Ltd
InTechnology Plc
Intergence Systems Limited
Interoute Communications Ltd.
iO1 Limited
IPL Information Processing Limited
iStor Pro Limited (t/a "iStorCloud")
Ixis IT Limited
Jadu Limited
JPC Infonet Limited
Kainos Software Ltd
Keane International (UK) Ltd
Kelway (UK) Limited
Lagan Technologies, Inc.
Learning Pool
Legal Escrow & Arbitration Services Limited
Liberata UK Limited
Lockheed Martin UK Limited
Logica UK Limited
Logicalis UK Ltd
Lumesse Limited
Magic Milestones
MDS Technologies Ltd
MEDLEY BUSINESS SOLUTIONS LTD
Memeonics Ltd
Memset Ltd
MentorWell Ltd
Methods Consulting Limited
Microsoft Ireland Operations Limited
Microsoft Limited
Midland Software Limited
Mouchel Management Consulting
Neontribe ltd.
Netcall Telecom Limited
Netpremacy Ltd
Network Resource South West Ltd
Network Revolution Limited
Newgrove Consultants Limited
Nexor Limited
Ninian Solutions Limited (t/a Huddle)
NTT Europe Ltd
Objective Corporation Limited
OCF plc
ONI plc
Onyx Group
Open Text
PA Consulting Services Limited
Parative Limited
PCFM Limited
PDMS Ltd
Penman Designs Ltd
PFI Knowledge Solutions Ltd
Phoenix IT Services Ltd
Phoenix Software Ltd
Piandi Ltd
Piran Technologies Ltd.
Probrand Ltd
ProcServe Shared Services Ltd
Prolinx Ltd
PwC
QCC Information Security ltd
Qedis Consulting Ltd
QinetiQ Commerce Decisions Limited
QinetiQ Group PLC
Quest Software
Quo Imus Limited trading as Qi Consulting
Rackspace Limited
Red Hat Limited
Redstone Converged Solutions T/A Redstone
Redwood Technologies Ltd
RepKnight Ltd
RightNow Technologies (UK) Ltd.
Riskex Ltd
ROC Systems Consulting Limited
Roketix Ltd
Sage (UK) Ltd
SAP (UK) Limited
Save9 Limited
Savvis UK Ltd
Scapa Technologies Limited
SciSys UK Limited
Sequence Collective Limited
SilkRoad technology
SkyDox
Skyscape Cloud Services Ltd
Smart421 Limited
Socium Limited
Softcat Ltd
Software (Europe) Ltd
Software AG (UK) Limited
Software Box Limited (SBL)
Software for Data Analysis Limited
Solidsoft Ltd
Speakserve Limited
Specialist Computer Centres plc
SportFocus Ltd
SQS Group Ltd
Squiz UK Limited
Star Technology Services
Steria Limited
Stoneburn Software Services Ltd
Strategic Blue Services Ltd
Stream UK Media Services Limited
SunGard Availability Services (UK) Limited
Symantec Limited
Symology Ltd
System Associates
System Associates
Talis Systems Ltd
Telefonica UK
TerraQuest Solutions Limited
thco Ltd
the 848 group
The Dextrous Web Ltd, trading as dxw
The Portal Partnership Limited
The Test Factory Ltd
ThoughtWorks Inc.
Thru, Inc.
TMI Systems Limited
Total Escrow Solutions Plc
Transputec Computers PLC
Tricostar
Trustis Limited
Trustmarque Solutions Ltd
Unboxed Consulting Limited
Unilink Software Ltd
UniServity Limited
Unisys Limited
UNIT4 Business Software Limited
Vaultium Limited
VEGA Consulting Services Ltd.
Venom IT
Verizon UK Limited
VESK
Virgin Media Business Limited
Virtual Internet (UK) Ltd
Virtuoso IT Limited
Virtustream UK Limited
Westbrook International plc
Winton Consulting Ltd
Workbooks Online Limited
Zumzum Limited