Cheapest way id say do a SPOA, you can fab your own stuff or buy a kit, Low Range is who id talk to, tell em your financial situation and they will work with you on what you can afford. How big are you thinkin you wanna go with tires and lift? Anything much bigger than stock tires and you'll need to regear the T-case.
If you want a bigger engine, its up to you. most ppl do the trackick 1.6 swap bc its the easiest and you get about 30% power gain.
whats your goal? 44s and a small block 350? 33s? honestly the sky is the limit and chances are someone on here has done atleast what you wanna do before or could help direct you