IMHO, you are way far on your Dart project from buying front suspension. You have all kinds of safety and realiablity issues to resolve first before buying any upgrades.
But after you get that all done...
An economical first major step would be:
Tire upgrade: 225/60/15 or 225/60/14 minimun. 16", 17" rim with better rubber would be great too.
front and rear sway bars. Hellwig if you are on a budget.
1" to 1.03" Torsion bars. The ones that go on sale.
Moog front suspension parts as necessary
Moog offset K7103 upper control arm bushings
Bilstein RCD shocks. KYB's on a tighter budget.
I'd try running that power steering pump pressure reducing deal the Ehrenberg wrote about in Mopar Action magazine before buying a rebuilt steering box just to get the firm feel.
All that will make it feel completely different/better for not a whole lot of money.
You have front KH disks right now. When you get them working properly, they work well with a starting suspension upgrade.