you can get some nice pickups which will help, but I think you could benefit from a Tubescreamer, they are the sweetest pedal for fattening up your sound, use it before your tube amp (set on clean) and whack up the level, you get the sweetest mildly overdriven tone which is rich and creamy and oh so smooth..

you can get the original specced OD-9 and OD-808 pedals from maxon (with the JRC op-amp) they aint cheap but they're 100% faithful to the original spec, and SRV used one, what more do you need!

in my experience, a P-90 or even P-100 pickup has a beautifully smooth, yet powerful tone.