i think wire wheel may be a bit agressive, i did a roll on liner on my 03 and spent 2 days sanding with 80 grit. there were a couple of spots that i wire wheeled to stop some surface rust (stupid drop in bedliners) but i just hit those spots with a couple of coats of primer before rolling in the liner. heres something i just found that may help you out
http://www.truckblog.com/1239-howto_install_linex_spray_in_bed_liner
good luck and document and let us see your progress
P.S. theres a write up in the tech section, its for roll on bedliner but im pretty sure the prep work is the same for roll on and spray on.