There are conversion kits out there, which would probably be the cheapest and easiest route, unless you want to spend some time mixing and matching junkyard stuff. For the front, you need fox body tbird/cougar LCAs because they have the spring perch and are the right length, but they have a different taper on the ball joint than the MarkVII, so you would need to either change the spindles, which I'm not sure if there are any that have the right taper and the 5-lug pattern, or press out the ball joint and press in ones for a MarkVII into the fox arm. For the rear, you need to either change the whole housing over to one that had springs, or at least cut the perches off and weld them onto your housing. I believe 94/95 mustangs have the right width rear axle, but the brake setup is very different, so you would need the whole rear brake setup off that car and change the brake lines to the mustang setup.
The only disadvantage to the conversion kits are limited spring options, and that if a spring breaks or something like that, you have to basically buy another whole conversion kit.
Also, I'm not 100% sure on these parts, I'm just going off memory from previous projects, so double check all the measurements before you go plunk money down on parts.
-91 Cougar LS, coming soon, complete overhaul
with a 427" Windsor.
-90 XR7 5-speed black on black w/sunroof, MP2, coated rotors, double intercooler, 15%OD, ported heads, comp stage 1 cam, 85mm TB, 90MM LMAF, 80# injectors, and ported big valve heads
-98 Mark VIII LSC, Procharger P600b, TR3650 swap and 3.73s.
-90 SC Automatic rustbucket winter beater
-97 Tbird Sport 4.6 Nice weather daily driver
-"Your buddy Mike is INSANE!" -ClintD's dad