I have looked pretty hard - not for HP so much as torque to turn larger tires with ease. There's not much available that can be bought as a planned kit.

The best options seem to be:

1) 4.3L GM drive-train swap (also gets you better x-fer case gearing)
2) 3.5L swap - I can't confirm that it'll work - conflicting information.
3) 3.0L stroker kit (to 3.3L) - $3500+
4) supercharger - you'll have to design and build your own, but it's possible. An Eaton MP62 would probably be ideal - lots of squirrels that might pop up later, though. You'll also need a boost dependant FMU, headers (or 3000GT/Diamante exhaust manifolds + custom exhaust work) and maybe a larger (or additional) fuel pump. With limited boost of around 6psi, an FMU and exhaust work the stock injectors should be ok and you might be able to push the early 3.0L to 195- 200HP.

Is it worth it? I don't think so - particularly when the change might set off an endless search for "driveability" and reliability/longevity.

It's cheaper to buy another truck.... but if you really want to do it - go for it.

Good luck,
Frank