2WD? 4WD? What axles? Any rear end upgrades planned?
Get a set of Stainless Steel brake lines for your disc set up front, big difference in feel and actual force applied to the brakes. Best "bang for the buck" you can get for brake performance, in my opinion. The front brakes handle most of the braking force on almost all vehicles, this is especially true of pickup trucks.
If I were you, I'd plan on swapping to discs in the rear soon. The stainless steel lines won't be much change on the drum brakes out back and it's cheaper to put discs in the rear than to do anything else. The big brake aftermarket is insanely pricey. The cheapest brake conversion I've seen for these is $500 for one axle, and the brakes were not impressive looking.
If you're in a 5 lug truck, you could get an entire OEM disc rear-end and stainless steel lines for half of that. New rotors and pads for another $150. New calipers would still have you cheaper. Plus you can get one with limited slip and the gear ratio that you want if you're picky. Also the added benefit that you can go to any Autozone, O'Reilly, or Napa when it comes time to do your brakes again.
You can go through it at your leisure, when time and money will allow, and install it when you're done. Rear ends are cheap to buy and cheap to go through.
There might be swaps to a bigger rotor and caliper from another GM vehicle that would be feasible (like 'Vette brakes on Camaro's). But watch out, because when I looked into that for my Camaro, the extreme prices of having to buy bigger wheels (and new tires to fit the wheels) to fit over them still ruined it for me. I'll now be waiting until it's painted and the wheels are picked, then just stuff whatever I can fit behind them into it, probably some C5 Corvette brakes up front and the disc setup off a 93-02 Camaro out back.