is this cam a good pick?

I might be able to get a good deal on a used Lingenfelter GT2-3 cam, so do you think it would perform good in a large truck like mine? (see sig.)

yup - especially with your "soon to come mods"

with 136,000+ on the clock is there anything else I should consider changing? I rarely drive the truck but when i do my right foot gets real heavy

Probably should do the oil pump while in there. Springs, pushrods and new seals should do it.