Talk to "patrick" ramjet gmc & gmc4cw "chas" chas has a shortbed pickup basically turned into a truggy. and patrick built a tube buggy. they can give you good insite on both methods. As for 1000.00 for a tube bender & 1500 for tube. Man you guys pay to much on the west coast. thats insane. you can get a decent tube bender for home use under 300.00 and you can get a 10pt cage from S&W for under 400.00 and then just add what you want from there. plus u got extra dough to buy the welder and tube notcher.
lol you could buy a welder, tubing, cage from S&W, bender, & notcher for the 2500.00 that you just figured for tube and bender! You dont need to buy mfg grade tools for home applications.
Also figure if ur gona do a tube chassis at least 10K from the start. not to mention drive train. seats fuel cell wiring blah blah. you can def save alot of money using the truck you have and build from there. You can reinforce the frame and add supports.