NoPistons -Mazda Rx7 & Rx8 Rotary Forum - WTB Gen 1 hubs and brakes

Hi, Im new here, im looking for some info on the 1 gen front wheel hubs and rotors. Im not sure of the difference of the 12A and the 13B hubs or which ones i need, I am doing a front brake conversion from drum to disc
on a 89 Daihatsu Hyjet van, http://www.rx7fb.com/images/smilies/icon_eek.gif yeah its not an everyday vehicle that people see or even know about but oddly enough it shares a few parts with the RX7.
I have purchased a set of bearings for the 79 Rx7 and the bearing races are the same but the bearings are different. This means my bearing will work in the 79 hubs and I could possibly use the front brakes from the 79. I can get the discs easily from Autozone or the like, the problem is they cant get the hub, im pretty sure people are upgrading theirs to 5 lug for larger brakes. Im hoping to find a pair of shelved hubs rotors and calipers from someones swap. Please let me know if you know where i can get these or let someone know im on the lookout for them.
Oh BTW the Daihatsu ive had for a whil, i swapped out the 35hp 3 cylinder 550cc engine for a 2001 Gl 1800 Honda Goldwing engine, 125 hp. I swapped in 75 Dana 44 narrow trac rear axle and converted the drums over to discs (2005 Ford Crown Vic disc/ 1995 Ford Explorer front Calipers and re drilled the axles and discs for 4X114.3) Harley FLH mufflers,Pretty fun ride, just need front discs now to finish. Thanks in advance for your help and any info.