That RAM would work but I wouldn't recommend it. The higher RAM would work but just run slower. Get the Corsair CAS = 2.5 stuff. You're on a budget and don't really need to spend the extra $70 on 3% better performance. I'll say it again: You don't need expensive RAM unless you are going to overclock, and even then A64's don't need hi-po stuff like P4's unless you are doing extreme overclocking.
Don't get the mobile chip. By the time you added the heatsink you were within $10 of a retail desktop A64 with a stock HSF which is a very good one btw.
I'd personally not get a "refurb" mobo or PSU, or really anything for that matter. Some goof probably shorted it out and they just put the "returns" into the "refurb" bin. Asking for hassles and I can tell that you don't need any.
Get one of the cheapie $70-90 Chaintech A64 mobos, they seem to be popular and good performers.