Bed condition + wood question - Pictures included

[Mrphoto]

So I'm new to the game...new to me truck and all.

It had a piece of sheet metal in there in the bed rattling around...didn't like that...I want wood!

So here are some pictures....please help me and tell me what my situation is please...what am I missing, do I have to do anything special to prepare for a bed kit, do i have to replace anything?

I think there's a fair amount of caked on mud...but there's rust too. Should I clean, scrub, rinse, dry and coat everything with some POR-15 or something first? Or are there major pieces that need to be replaced/purchased?

And this is a 'daily driver' build, not a restoration if that helps clarify my next steps.

Is Mar-K THE BEST place to go for bed kit? Thanks!!!