Shibboleth Developers

We are plannning to purchase a test server for the purpose of testing 
shibboleth IDP. We are going down the unix route and have not decided on 
linux or solaris. We have priced servers for solaris 10 and have come up with 
some of the following sparc stations :

SunFire V210 1 cpu 1 GB RAM 73 GB hard drive

SunFire V210 2 cpu 2 GB RAM 2 * 73 GB hard drive

SunFire V240 2 cpu 8 GB 2 * 73 GB hard drive

All of which are very expensive. 

Does anybody have any views on the hardware requirements (remember this is 
for testing purposes, but we ultimately wish to use the same 
hardware/platform for our live server, allbeit one which has a higher 
specification). Also does anyone have any preference for unix or linux in 
relation to shibboleth IDP.

Many Thanks

Martina