I've pulled 80 tanks several times by myself. I've never drained them before lowering them, but it would make it a lot easier. I've always just run them down to about 1/8 of tank. There are two straps to contend with and then the Ebrake cable is a PITA. Getting to the pump is real easy under the middle seat. Pulling the pump takes less than 5 minutes. If I were you I would probably pull the pump, siphon the tank and then remove it. Then use the floor jack to lower it.
Personally, I'd have it welded or get a new tank. Andre's offer of a $150 is a good one. You'd have a spare pump and sender in case you need one. Or you could use it in an aux tank. Heck, if it was me I'd use Andre's tank and then cut the sender mount out of the tank with the hole in and order up a fuel cell and have the Toyota pump and sender welded on top of it for an Aux tank in the spare tire area. I'd actually get really tricky and cut a hole in the body in the rear and weld in the factory access cover found under the seat from a wrecked Cruiser. So if you ever did need to replace a pump you didn't need to drop it. Toyota gets an A+ in the engineering of that access cover. I'm actually going through all this right now as I have a 60 series tank I'm going to use in my 3FE powered FJ68 (60 body on 80 chassis).
If I was further along with my project, I'd offer you my 80 tank in return for your top of your tank, just the sender/pump mount. I'm not 100% what all I'd need to make this project go right, so I'm not ready to part with it yet. I guess if you use the screw method you could keep that in the back of your head and give me a shout in a few months.
As far as I can tell from my rigs and the ones I've parted all the tanks are the same 91-97. So finding a used tank really shouldn't be that hard. And most 80s in the boneyards are rollovers or frontal or back damage. Most have perfect tanks.