At this level in the product space, yeah, this is good stuff. The Dell and HP gear I have worked with that is in this market space is usually very good. And since they stock spares and give you a well defined service model, there is some protection to your investment. The parts are quite similar between the two, so either is good. They are the top 2 in the server space, I believe.
That being said, for people like me who want to be bleeding edge, or boutique, or have special parts requirements... then you go to the other guys, such as: APPRO, Aberdeen, ASA Computers, Iron Systems, RackmountPro. Those guys will give you 1-on-1 exact build service. But you will pay more for the privilege.
If you want to fudge, you could save $$$ by going 4GB and going SATA. But you would have to judge. You understand the memory issues of your app better. I/O may be better on the 10KRPM SAS drives, but I think the LSI controllers that Dell is using will be quite good in either case. HP has nice controllers as well.
If I were trying to be cheap, I would go straight SATA, and then use software
raid under Linux. But I have *lots* of experience with that, so I probably wouldn't
say this is a general recommendation. I think RAID5 on the SAS controller is
the safest bet, if you got the money.
