From the looks of it, you might have stock Gibson pickups which I find to be nice and smooth and warm on the bottom end not overly mid focused or gritty on the top end. (Beautiful bass BTW, love that ruby sparkle finish). However, your bass doesn't appear to have any tone controls, just a kill switch or pickup selector toggle. So you'll have to do all your tone shaping on your bass rig.
Not sure what strings you're using, or what rig you have, what type of music you're trying to fit into or what your tone goal is, but I gotta say I have yet to find a type of music the stock TBird with an onboard tone control can't fit into. I would assume your bass rig has every bit as much if not significantly more tone shaping capability than the onboard control does, so I'd look to a string change and amp tweak before I dropped several hundred bucks on new pups.
If new pups are in order there's plenty of choices in the premium market (Lull, Lollar, Thunderbucker...) and some good choices in the bargain market (China buckers, Eppi VP/Embassy Humbuckers...).
With a bit more info on what you're after I'm sure this uber enabling clan here in the club can come up with great ways to help spend your money.