Everything you need to have a modern handling torsion bar suspension.
1.03 PST torsion bars -------------------------------$263 (you could go bigger here too, 1.06", 1.12" etc, but for an early A you wouldn't need to unless you're going to autoX)
Tubular UCAs (PST, FFI, etc)------------------------$350
Adjustable strut rods (PST SR 14385)---------------$279
Solid tie rod sleeves (PST SAS 440S)----------------$49
LCA boxing plate (PST LCAPLTMOP621)-------------$14.50
Greasable LCA pins (FFI w bushings)----------------$135
Helwig tubular front sway bar 1 1/8 #55905 (73+ K)--$175
(#55917 for 67-72 K and large tires --- $263)
Solid rear 3/4 #6907--------------------------------$237
Mopar oval track springs
Zero arch- P4529414---------------------------------------------$232
1" arch- P4529415
Energy suspension 1" shackle bushings 2-2117G----$9
Bilstein RCD shocks(RCD-70-56663)------------------$410
Grand total on that is about $2,200, that's got a little extra built in depending on where you shop.
From there you can add a Borgeson power steering box kit for $859 from Peter Bergman, or a Flaming River 16:1 manual box for $635, or even a brand new 24:1 manual steering box from P-S-T for $419. Still all worm gear units, but they wouldn't be worn out.
Finally, you'd want to address your brakes. The reason they aren't included above is, well, they aren't included in the RMS price tag either. That's $5k and you still have to buy brakes on top of that! Anyway, you can get a 73+ 10.95" mopar disk kit from Dr. Diff for about $530 depending on your options in the kit. That includes spindles, bearings, calipers, hoses, lower ball joints, pretty much everything you need. And all OE type parts, so, you can buy parts anywhere.
So, if you add all that up with the most expensive steering option, the borgeson power steering kit, you get about $3,600. BUT, that's the front suspension, steering, brakes, shocks AND rear suspension. Not just the front, and not the front without brakes. And you could still do it cheaper, use moog k7103 offset bushings and tapered adaptors and keep your stock UCA's, use your current steering box, etc.
As far as coilovers vs torsion bars, I've said it plenty. Springs are springs, shocks are shocks. Coilovers are nice because they still have more spring rates available and they open up some space for headers, the biggest advantage to the conversions is still the rack and pinion. But, they raise the CG of the suspension parts and put loads on the chassis in places that it was not designed to carry suspension loads. So IMO you must strengthen the chassis, and specifically the front (inner fender braces, J-bars, etc). Torsion bar suspension is still widely used, from semi-trucks to the new Ford GT supercar (yup!). It allows for easy ride height adjustability, a low center of gravity, and it keeps the suspension loads in the K frame and crossmember where the chassis was designed to carry them. Plus, the market for shocks has improved dramatically in just the last couple of years, and you can get a pretty decent selection of spring rates from all the torsion bars out there now. The steering box is probably the biggest drawback, the space isn't that big of deal if you just get a set of TTI's or Doug's. Yeah initial install is a pain, but, unless you're constantly pulling your engine or dropping your headers it's not an everyday kind of problem.
