you going to need something similar to:
1 * XTA2510R01A2N12000 - £11067
Sun StorageTek(TM) 2510 iSCSI Array, Rack-Ready Controller Tray, 12TB, 12 * 1TB 7.2Krpm SATA-II drives, 2 * 512MB cache iSCSI HW RAID controllers, 2 * redundant AC power supplies, 2 * redundant cooling fans; Includes Sun StorageTek(TM) Common Array Manager software and 2 * storage domains using Sun StorageTek(TM) Storage Domains software; RoHS-5
That would solve your initial storage requirements,
You would then need to expand with the following expansion trays (you can add a maximum of 2)
XTA2501R01A2N12000 - £9021
Sun StorageTek(TM) 2501 SAS Expansion Array, Rack-Ready Expansion Tray , 12TB, 12 * 1TB 7.2Krpm SATA-II drives, 2 * SAS I/O modules, 2 * redundant AC power supplies and 2 * redundant cooling fans; Includes 2 * .5m SAS host cables; RoHS-5
Then you would need to start again with another controllor tray and carry on as ur data grows,
Another option would be something like the X4500
A76-PPZ2-16G-SMH - £32550
Sun Fire X4500 x64 Server: 2x AMD Opteron Model dual-core 290 (2.8GHz/1MB) processor, 16GB PC3200 DDR1/400 (8 x 2GB) memory, 48 SATA 3.5" 1TB 7200RPM HDD; 48TB, 2x PSU, Service Processor, 4x 10/100/1000 Ethernet ports, 4x USB 2.0 ports, 2x 64-bit/133MHz PCI-X slots, VGA port, no power cord, order Geo-specific x-option. Solaris 10 OS preinstalled, includes Slide Rail Kit and Cable Management Arm, RoHS-5.
Dropping in price to £12648 with 48 * 250gb HDD's.
If your company has been going less then 4 years, or you develop on software then you can 1/2 those prices
Lease / finance easily sorted