Of the two, I prefer the Wilwood's. I have the Wilwood Dynalite II's on my fiero. I have the SSBC on my 66 Vette and had them on the front of the 66 mustang (SSBC Force 10 calipers)... Glad I got rid of them for the mustang and went standard GVM. The GVM's were the way to go on the mustang (front strut conversion done with 11 inch rotors.) The SSBC were twice the weight (if not more) over the wilwood's with no improvement on how it would stop. However, the Wilwood's are not DOT approved AFAIK, where SSBC have calipers that are.
Doesn't really answer your question, but I thought I would chime in with my thoughts about the two companies. Try contacting HT Motorsports about it, they may have the adapter plates you would need.
