Is swaping that hard to do or is it an entirely different setup all together

cant put a LSx intake on a TPI motor

not at all? Can you put a camshaft from an LSx in a tpi engine

No, do you have a lot of LSx stuff?

most lsx stuff wont fit TPI engines...cept the fuel injectors i understand

..and maybe the roller lifters.

The LSx engines are pretty much entirely different animals than the SBC.

Cant use the cam. Bearing diameters are different, firing order is different, and most importantly the order of intake and exhaust are completely different. The spacing and length may also be different, but doesnt much matter. Cant use it. Or the crank, pistons, heads, headers, and a number of other items.

An LS1-style engine is more different from a small block Chevy than a big block Chevy is.

What kind of upgrades could I add then

Read the tech articles, the FAQ, the tech data, learn something from them, and then ask if you dont know. There are a million things you can do to a thirdgen, exhaust, suspension, intake manifold, headers, cam, heads, interior, audio, its unlimited.