I think I would use the hubs, since you have them complete with brakes and all. I used auto ball joints to connect to the a-arms I made. Was going to use heims but I dont like them laying flat and couldn't come up with a way to modify the atv spindle. My frame mounts are vertical, so I layed the atv spindle lug bolts down measured the distance from table to lower mount, distance from table to upper mount and the differance was how much shorter I made the upper a-arm. If you use heims for the a-arm to frame mount them you can do adj therre to get camber right. Does that make sense? I can take off wheel and post up some good pic to help clarify if you need. I have 8" center frame, 10" steering rack, 22" a-arm inc ball joint. Fronts about 6' wide overall.
Otherwise I would scrap the atv stuff completly, but for the size of buggy it could work.