Your next step is to determine whether your machine has Merom or Penryn motherboard. Merom CPU's were mounted on Penryn based motherboards on newer T61(s).
doesnt really matter. Flash middletons BIOS and the laptop becomes golden
that video card overclocks as crazy. I run it at 600 core / 925 memory all the time, but it used to be higher. Been like that for 3.5 years, lol.
8GB ram will cost you quite a lot, and is really pointless unless you run 64 bit win 7. Some say that you can run cache memory in the upper addresses even if you're with 32 bit OS so that it would speed up your HDD, but I haven't tried it yet. Instead I run fastest memory that comes in 2GB modules max, with timings 4-4-4-12, which is naturally ~25% faster than the regular 5-5-5-15 modules. Not that you'll notice it though.
CPU-wise you can run Dual IDA after you flash that bios. This is how I run mine at 2.8GHz all the time, heh, priceless. You can also overclock the CPU, but it's harder.
good luck. IMO, this is the best T61 out there, as other are too big
Only negative would be that you probably dont have ExpressCard slot, but anyways. It's really useful in my case as I got me eSata card for it - works awesome too