Converting 2wd `98 to solid-axle 4x4?

[YBHIGH]

I recently bought a `98 Chevy ext. cab SB 2wd with the 305 and 5spd.
I already ordered the lowering parts and some other engine performance stuff.
I decided to go with the 2wd because it will be my daily driver and I needed the best gas mileage possible, and most comfortable on the highway. It currently gets 21 mpg even before I replaced a bad O2 sensor and replaced the factory cap and rotor.

So, I'm thinking that in a couple of years, I will be wanting a 4x4 again and can get a cheaper vehicle to commute in.
I would like to know what options there are in converting the truck to 4wd.

I did this to a `66 F100 by mounting the body on a `76 F150 frame. Worked pretty well and wasn't too hard.

With my Chevy, I know that ORU offers straight-axle conversion kits for the 4wds, but do the 2wd and 4wd have the same frames?
I'd like to swap in a Dana 60 front, Corp 14-bolt out back, with a NP205 transfer case.
I'd like to run 37s.
I assume this has been done before, any links or advice?
Even though I wouldn't do this for a couple of years at least, I'd like to start collecting parts now to be ready.