Welcome to EBPF, 8nutz8, congrats on what sounds like a really sweet deal!
Correct on TStat options. Can precede tune installation if you want.
Motorcraft SP534s work fine, if you really wanted to, you can use the NGKs instead. I think they are one range colder. But unless you are running a hipo setup, I dont see them as being NECESSARY. The TStat helps quite a bit in that regard. I know bpd1151 runs the NGKs, hope he chimes in with his thoughts.