As it happens, as I'm breaking a TF I have all of those parts available if anyone wants to make me an offer!
Personally, I find the brakes on my Spyder pretty progressive and as you have to press quite hard you'd have to be pretty brutal to lock it up unless you were on a slippery surface (in which case I'd probably be driving the tin top!)
ABS is definitely a great safety feature for daily use though - I'm fairly convinced I've avoided two accidents by having ABS on the car that would have definitely been crashes without it. I'll look forward to your build notes and lots of pics