welcome to the forum. sounds like you got a nice truck. post some pics.
a quick rundown from my own research as I struggle through my own project:
out side of a major rebuild, it's a bit tough to get a significant more power out of the 360/5.9 magnums. the stock cams and heads aren't great.
if you want to go just top end, you could add some power with some edelbrock heads, hotter cams with maybe matching intake manifold and EFI. Hedman long tubes are pretty nice too. Only ones that seem to fit between the engine and frame rails. all that is still a lot of $$$ and you'll probably want to pull the motor to get all that done, or at the very least the front core support.
of course, Holley just recently put out a hemi swap kit.....
no real support out there for suspension parts. lowering will take some creativity. putting lower control arms off a dodge van will get the front lower. as well, there is a quick ratio steering box available but will cost you.
enjoy!