David,
I think Windows 7 Home Premium is sufficient for mostly anything. Here is a comparison between Professional and Ultimate:
http://www.intowindows.com/differenc...mate-editions/
I notice Dell don't even offer a 32 bit Windows version - 64 bit all the way, and RDSS runs sweetly on Win7 and Vista 64 bit! That base computer certainly has everything you'd need to run RDSS now and in the future. Any problems that RDSS has now with memory is not the fault of insufficient hardware - it's the software's own internal memory intensiveness, and Version 2.0 seems to have solved that.
I'd recommend you check out the screen resolution(s) available from whatever video card (chip) you choose: it really is convenient and using the full potential to display the Analysis screens as a 3rd panel at the bottom of the screen and for that you need 1024 or 1050 vertical pixels (as in 1280 x 1024 or 1600 x 1050). There will be a few more screen layout options in 2.0, for example displaying full page Analysis screens side-by-side with horses' PPs so displays like 1440 x 800 can show 2 PP panels with Analysis on the side. But the option of more screen height gvies you moe, well, options. RDSS 2.0 on a 1600 x 1050 resolution 24" monitor looks gorgeous, and lots of screen width for everything you could hope to display.
The only thing I can think of is software like MS Office. If you want to splurge, get more memory. And make sure you get an external USB backup drive - they're dirt cheap. Then use it - daily!
I've owned Dell laptops for years and run 2 of them now. When I buy one, I get the top of the line and try to push it for 4 years. After 2 years, it's middle of the road and after 4 years its low end.
Any other specifics I can help with, just let me know!
Ted