I hope you meant "a" RAID card and not Apple's RAID card!
straightryder, if you really want a good advice (which I assume considering the budget) on which Mac to buy, please create a new post with your questions in the Mac Pro section.
There are lots of people who really know what they are talking about and can help you, specifically in means of storage questions. Just keep your eyes open for nanofrog. I'm sure he can answer all of your questions!
Okay, thanks