Okay the pickups you listed (DiMarzio Evolution and Texas Special) are used only in 1 Jag-stang: KURT COBAINs. All other Jag-stangs use a Fender Japan 57-62 pickup in neck and a low output generic humbucker. Mustangs use in all cases use basically a modified Strat pickup from the time (Vintage use American made, Japanese use well Japanese.)
The Kurt Jag-stang sounds much like live In Utero Nirvana, normal Jag-stangs sound similar to Mustangs but a bit warmer.
The Mustang will fit a JB Jr, it is single coil sized and will sound much like Nirvana (in fact i think Kurt used it).
As for Foo Fighters sound, early stuff you will get with a Mustang, but anything after Color and the Shape, you would need a Gibson thru a Mesa stack.