Ok well you willl notice with the more expensive ram, it has Heatspreaders, and other things to aid in overclocking. the Fast / Value comes in when you talk about CAS latency. the faster ram usually has a CL of 2 whereas the less expensive stuff has a CL of 2.5 and usually is just a chip (no heatspreaders). In your case, since your not overclocking, PC3200 will work fine. It will run at the 400MHZ max that that mobo supports, unless you up your FSB (the FSB is 800 but it is quad pumped compared to double so 4x200 not 2x200) it equals out to the same anyway.
If you were planning on getting more RAM later, get 1 512mb Stick of Corsair XMS or Kingston Hyper X, these are my brands of choice. The reason I say one stick is that the Dual Channel wont make THAT much of a difference, and if your getting more later, it would be better to have 2x512mb sticks in dual channel then 2x256 in dual channel and 1x512 on its own. (I still suggest you go for a GB and get the CL2.5 stuff but thats beside the point)
About the Proc. Keep in mind that Intel is switching to the new socket in the summer time, so you probably wont see any more then a 3.6ghz CPU on Socket 478.
Hope my suggestions help, and dont just confise you more. buying a new system is always a bitch. I hate getting something like this because there is always the "if I only spent X more amount of dollars I could of had something I really wanted" I know I do this all the time. I just hop that my new DSLR (D70) wont be like that
