looks like a cherry little truck, id keep it the way it is..
but if you MUST do something, I'd say pull that 6 cyl out and give it some pep.
Ive always been a fan of being different, and i always wanted a fast 6 cyl ( i think they sound really cool when they turning at like 6500 rom

)
Id say lower is, but it looks as though you do some towing, so you dont want to sacrifice and spring travel.
i think a 6cyl sleeper would do the truck