Before id even try to adapt a rack & pinion, id look into the Superrunner steering setup from Superlift. It uses an idler arm similar to what chevy did with their early IFS systems, and apparently works pretty good, but it only works for lifts of at least 4". But, it might help to design your own. Personally, i wouldnt even consider rack&pinion on a TTB truck due to the way the suspension moves.
Getting the steering tighter is not just one thing. Its a bunch of small items that all add up to a good handling vehicle.
New pivot bushings & radius arm bushings, if theyre 10 years old. Sway bar bushings too. Tie-rod flip if the angles are severe, or a drop pitman arm. Even a stock pitman arm from a F250 or F350 can help level out your tierods, which will help a lot. Definitely a Redhead steering box (ive got 2, theyre amazing) or a Bluetop. Either way, you want a better steering box than what youll get at the parts stores. Saginaw pump helps too. Then, you either rebuild your stock steering shaft, or buy a Borgeson. (That rag joint doesnt last forever!) Also, how is your steering column? Tight, or are the bearings getting sloppy? That will help as well.
As for your ABS question:
@Kingfish999 brings up a very good point: the Ford 9" rear doesnt have the provision for the ABS sensor. Yes, there are kits out there to adapt one. No, theyre not cheap. It would be cheaper to put in a 8.8 rear. Then you can get the HCU (hydraulic control unit, aka the RABS module) & the ABS ECM out of a RABS truck, plumb it in, and wire it up. The harness is fully integrated into the vehicle so youll have to cut the pigtails out of a donor truck, and then wire it yourself. It is standalone (it doesnt need the ECM to work), so it would definitely be possible.
If you wanted 4WABS, you will need to switch to the knuckles & spindles from a 94-96 truck, because they are 5 bolt spindles instead of 6, in order to make room for the wheel speed sensor. The wheel bearing hubs as well of course, since thats where the tone ring is. Then, same thing as before: get the HCU, all the sensors & pigtails, and start wiring! its also standalone, but fully integrated into the truck harness so youll have to wire it all yourself.
Either way i do think its possible to do, but its gonna be a lot of wiring to do it.