The box and layout of the steering is the same on the 220 and the 142. How much difference is there between your cars? Wide wheels and big tyres add little to the driving experience IMO and putting a set on a car with less that 100% condition suspension and steering can make things pretty unpleasant on a bumpy road trip.
If there is a thread or two on the adjusting screw after the locknut is done up your box should function almost as good as new. Yes there might be a bit of galling on the worm, not good and the bearings might have started to break up due to it running without oil. Bushes wear and the bottom seal goes. Seals bushings and balls can all be replaced but the worm cannot. If in reasonable condition and properly adjusted it should steer pretty light once you're on the move. A new box had about 1" play either side of centre and you might have up to double this but that doesn't seem to matter when your driving. All of the suspension joints need to be good and the idler shouldn't have any play. With just a fraction of toe in it should run down a flat road hands off and steer itself so to speak. It will never have the instant and direct response of rack and pinion but the feel is friendly enough.
Ez-Power will lighten things up and allow a smaller steering wheel, it's also adjustable for weight, but it will still be using ye olde steering box.
You say you've been doing some reading so there's probably not much there in the way of new news so maybe refurb what you have even if it means finding a better box. The stockpile is getting smaller, especially for Amazons but you'll find a 140 one without too much of a problem. Good Luck.