You can use Blazer bucket seats, but you can't use Blazer seat trucks. They won't fit. If you have some fabrication skills you can fit anything in there. The only "boltup" thing there will be is the factory bucket brackets. And they are hard to find.
Without cutting the frame a 6' bed won't go on there. Bed prices vary from state to state, but they usually run around $800-$1000 for a LWB and $600-$800 for a SWB in GOOD shape. Where are you located. I have an '82 that I am parting out, I am located in Birmingham, Alabama.
For the steering column, you will need to swap to a manual column (tilts are RARE to find) or just remove the auto lever and over look it and put a floor shift in it.
Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project