3 point seat belt advice- what years and where is the best place to find???

[1970blazin]

I am putting a custom aluminum roll bar in my 70 blazer. I will be able to attach shoulder belts to the roll bar for both the front and back seats. My question is what is the best shoulder belts to use for this purpose? I know that the s-10 belts will work (87-92??) I know julionos and some of the board vendors have aftermarket ones, but I would rather not spend the $80 a set. (I need 4 sets--ouch! )
If I want all four to pretty much match and am looking for black- what are my other options?? Anyone seen any nice ones in the junk yard or am I crazy to think I could find anything like that? Any advice is GREATLY appreciated...I just want this blazer to be real safe for my family!
Thanks-
Diane