The OP mentions a budget of two grand.. I don't think any frame or front clip swap could happen for two grand, especially if OP can't weld and fabricate and do wiring, and if you change the WB on the swap frame there are Ackerman angles to consider.
I'd think the taller rear gears vs T5 or NV3500 (probably where I'd go, I was never hyped on the T5 for durability behind the original four popper, let alone a bigger truck) conversation is the one to have, for two grand. Also yes on springs and kingpins replacements, then have it aligned and the caster angle checked.
