Scout D20s are very easy to find if you look in the right places. Contact JPScout on this board and put out a request for a D20 here ...
http://www.binderplanet.com/forums/showthread.php?t=71481
Scouts rust away before the drivetrains are worn out. The remaining parts can usually be had pretty cheap.
Nice scout. A little tall for me, but a great start.
For your draglink, you could go highsteer (expensive) or you could make a new big DOM Z-link if it's just a trail rig.
You'll need DOM, ES150L & ES150R TREs, tube adapters, jam nuts, decent welder, paint.
The TREs are cheap at Autozoo and will fit in the scout knuckle. They will not work with a stock draglink or tierod.