Sounds like you want to go w/ coil springs and ladders. I have two ways you can use fully functional ladders w/ leaf springs too. W/ coils, you also need a panhard bar to keep the rear from moving sideways. here are a few version of a panhard bar;
The third one is preferable - the longer the bar is, the less lateral movement as the bar swings in an arc as the rear goes up and down.
The best lateral locating system is the watts linkage shown below. With this setup there is zero lateral movement no matter what the rear does up and down.
The coil spring mounts can be as on a stock Oldsmobuick or fancy coil overs, doesn't matter. I'll assume you know what you want and how those work.
As far as the ladder bars go, weld them up using cold rolled steel tubing, square or round and make them strong. They can be any shape as simple as this,
or fancy like these I found on some web site,
Commercial units usually come w/ 5/8" spherical rod ends at the front but I prefer to use 3/4", especially on the street. Want to stay alive after all. Front mount should be strongly welded to the frame or bolted to it w/ 4 grade 8 1/2" bolts. Use grade 8 fasteners throughout.
A lot of commercial T-bars show a bolt on attachment to the rear axle. DO NOT do this. The rear T-bar brackets MUST be welded solidly to the axle. A T-bar works by preventing the axle form twisting from torque on accelerations and there is no U-bolt in the world that can be tightened enough to prevent twisting of the axle. At the rear of the T-bars use two 5/8" clevis' on each bar. the mounting points should be ~6" apart to provide the leverage to prevent axle twist. Do not try to get away with a single mounting plate welded to the axle on each bar. Healthy engines can twist single plates right out of the weld on the housing. Use two 3/8" plates for each bar and design them to wrap the axle housing a full 180deg.