So you have to ST Bern's? DAMN! You better buy an HD pickup, lift the thing for better G.C. and throw a cap on the back for the dogs.
that'll give you all the space you need for the tool box, keep the slobber out of the front seats and still give you room for five passangers.
I have even seen a 2500HD Quad cab lifted higher than my 5"7" frame could see. He had 37's on it and was out on Hell's Revenge in Moab.
As far as the cheaper than 55K.
you could by a new H2 with an Adv. package. a lux will get you around the 60K sticker price.
Or get a Burban and lift it if the H2 is not enough room, but you would have to do some work to that too.
I think a year old H2 Lux or a not fully loaded one will fit your needs.
Good luck.
there are a few used ones for sale on this forum also.