Leave the bed on, but tube it out with the bars going through the bed. Leaves much more space that is easily usuable, but adds a ton of strength in case of a rollover. I think you have probably seen this pic before, but anyways:
His is not finished yet, when we will finish it I don't know, but something like that is what I would suggest. Definetly add a X in the hoop bar if you do not have one, a rollbar won't do much without one on a hard hit.
Dovetailing it looks cool, but if you leave the bed it won't help a ton, just cut about 13" out of the bed and leave it like that, don't leave it stock length though, I still scrape my bedsides (not sure on what), because I have a dent in one of them, I think it might be from the waterfall at Callalantee, and they are shortened and dovetailed.
EDIT: And also, he has since trashed the bedliner and did a Herculiner which looks MUCH better, he also made a storage drawer which the tire now sits on top of.