rear axle setup on 55-59

[TK56]

So I just got my c4 corvette IFS on my 56 chevy shortbed, installed using the progressive kit ! and I kno the ideal thing would be to put the c4 irs in too but trying to spread my money out and going to college next fall too. I want to get disc brakes in the rear as well. So if I buy a 10 or 12 bolt rear axle how should I set it up? with 4 link or coil overs ? leaf springs? trying to figure out what would be the most economical to do. maybe 500 bucks, no more than a 1,000