9" swap questions

[steigst]

Could anyone tell me which donor axle I should be looking for? I have been on google trying to collect info on the swap but I have seen a lot of different answers regarding which features/widths are most desirable. I currently have a 12 bolt w/ 3.08s and I want to put in a full spool but don't want to deal with c clip eliminators. I figured a 9 inch would be a better option if i wanted disc brakes, a spool, and still retain the ability to make a quick trip down the highway. I don't want to buy a complete setup or housing, I'd like to do it myself.

500hp bbc in 4000lb 77 stepside with MT 295/65-R15

thanks