3rd times a charm...67-72 DD

[hotcorner216]

So Im new to the forum but not to c10, ive owned 2 in the past but life got in th way and had to get rid ofboth...now that im passed that im really wanting a 67-72 short bed To make my DD...iv been looking for a decent one in my area but all are 8k+, ive found some decent LWB for around 2~3k, ive done reading on the forum see getting it shortened would be more cost effective, as far as strengthg goes, if i want to turn it into a 500hp canyon carver in a few years, is it safe/smart to do? After shortening the bed 5.3l w/ 4l60e would probably be next....but ill save that for a later time...any advice
/input appreciated...

Lastly, anyone know someone reputable in the so cal/IE/ OC area who does good work and fair priced? Thanks