Guitarist: Got a les paul vs strat question?

ok so i have 2 a les pauls and i absolutely love one (the standard-which is heavily modded), and i hate the other( the studio). ive decided to sell the studio, and lately ive been desiring a strat sound. do i use the money from the studio (about 500) to buy a used strat, or to have a 3rd pickup installed in the midldle position on my good les paul (which supposedly sounds like a strat). The other thing is my lp gets really heavy during long gigs, and i might want a lighter guitar. also, i loooooooove strat necks.