Thanks for the replies.
Tobin went to a good deal of trouble to write me a SOLID email-reply. Tons of info, aimed right at my level, and really shone a light on the situation.
Without realising, I'm kinda going about things backwards, and I'm going to need to double/triple my rubber budget. That's fine. This car's a keeper, and I would've spent the money anyway, just over time. Instead: I'll do it all now, matched.
The suspension is pretty-horrible, and will effect my other decisions, so I'll need to include that in my decisions/purchase too.
I need to spend some more time reading/learning, and nail-down a lot of these variables. So for-now, I'm off to the suspension sub-forum.
Looks like I bit-off too much with my first thread. Down She Goes!