I think Gerry hit on mostly everything but i'll throw some input in and some options I explored/the pros and cons of them.
So stock tank would work, you can even mount a twin pump setup in the stuck bucket. The biggest issue is, as already mentioned, baffling. The stock tank is terrible, I have starved a stock pump doing donuts with nearly a half tank and a pump capable of feeding 500whp with boost is going to be sucking a lot more fuel from the bucket a lot faster. If you only drag race the car and keep the tank over half, you'd be fine, but if you ever plan on road racing, doing donuts in a parking lot, powering out of a long turn etc... I'd stay away from stock. Just too much risk with going lean under boost from fuel starvation.
Option two is a surge tank/swirl pot. As 95 Wagon mentioned it's just a small tank that gets fed by your stock tank/in tank pump and then feeds your motor via auxiliary pump(s). This is THE best option for fuel control, if sized right you really can't run this dry. Only reason I didn't go this route is just because I couldn't find a good spot I felt I could safely mount it with my build and I didn't really want to have to worry about having 3 fuel pumps since I'd need two for my engine side of things. I think if I could do it over, I might have went this route instead though and looked a little harder for a good mounting spot for the surge tank.
Option three is what I did, an automotive phantom system. They sell these with a single 450LPH, dual 340LPH (what I run) E85 compatible, the dual option is good for 1200WHP on pump and probably over 900whp on E85. You cut a hole in the top of the factory tank, drill some holes and the hat bolts in with a special foam gasket. They include a foam bucket that goes into the tank and acts as a baffle. The hat has a return, two feeds and a vent built in and the return feeds back into the bucket to help keep the pumps submerged. Supposedly the fuel control on this system is great , and I've got maybe 3k miles on mine so far with some track use but haven't had an opportunity to really test the limits with lower fuel levels yet.
Only downside to this is the hat sticks up about 1/2" and didn't clear the floor where I mounted it, so I had to cut little bit of the trunk floor to clear the hat. I actually made it look factory by blending the notched area with the factory hump and welding up a sheet metal access hatch for, but that is just cosmetics. Benefits now though is I can access both the sending unit and the fuel pumps with the turn of a few wing nuts. You could also probably space the tank down somehow to give you the floor clearance.
Option four is a fabricated fuel tank. A couple people make fabricated aluminum fuel tanks for our cars with rear mounted sumps and AN feeds to an external pump. Another great option for fuel control, but they are pricey and definitely don't look stock (could be a good or bad thing depending who you are).
Option five is to sump an 80's caprice tank by welding something like an Aeromotive or Competition Engineering sump into a stock steel tank. I've done this before on older cars and was going to do it in mine, but the only sump I really trusted for good fuel control during both lateral G's and acceleration was the Aeromotive and it is bulky and hangs low. On a lowered car I was just worried it was something that could potentially be damaged easily be backing into a parking space with a tall tire stop or something.
Option six is a fuel cell
Option seven, and I don't recommend it but I have seen guys do it, is a diesel style fuel sump fitting in a stock tank. They sell them for trucks, they are just little fittings that sandwich into a stock tank to give you a feed from the bottom of the tank to your external fuel pump of choice. They don't really provide much baffling at all though. Probably fine for 1/4 mile but probably poorer fuel control in a turn than even a stock bucket.
