New rust bucket truck

Well i've bought a rusted out 1980 Datsun pickup. when i say rusted out i mean rusted out from the bed to the floorboard and almost everything in between. I'm going to have to start from scratch with the floorboard (any Ideas that work?) the bed i'm debating on just cutting out the bed floor and tacking it to the frame so i can tuck bigger wheels or just rebuild it too. I need help from people with experience with these pickups. I need to know which websites if any offer either interchangeable or the actual parts for the engine, body, and tips to help me i'll post some pics as soon as i can so you know what i'm looking at here. :)

i have a 80 datsun too . i get a lot of my parts from pullapart.com.they are a lot cheaper than going to auto dealers and they list what vehicles they have on their website.