1989 Chevy Silverado 2500 fuel problem

Ok here is the deal 4 months ago my fuel gage starting acting wacky never was correct. Not to bore you with the details but about 2 months after that I was driving it and it just quick running and would not restart, after doing a few checks I figured out it was the fuel pump. Took it to the shop and they told me that the fuel pump had came loose and was bouncing around in the tank and eventually it failed and that is why the fuel gauge first was inaccurate and the eventually the pump failed. And to fix the problem I needed a new fuel pump, Fuel pump strap, and gas filter, relay and tank sender. So after the tow bill, parts and labor I am out $1000.00.

Ok now it is 2 months later and after leaving work yesterday on the interstate and the truck just dies... After about 1 min it will start for maybe 20 secs and die and will not start for at least 1 min but only for 20 seconds. So I again traced it back to the fuel pump so I figure the shop messed something up and had it towed too them and figure worse case it is under warranty (And oh yea, about 2 days before this happened the gauge was acting up again).

Now they told me that the new fuel pump unit has came lose again and some times that came happen when you replace the fuel pump because the fuel pump might not mount to the tank properly because of the age of the fuel tank. And since the fuel pump is probably loose, but they cannot tell for sure unless they drop the tank and check for sure. But they are pretty sure that is the problem after doing all of the electrical test and the only thing they can find wrong is I am blowing a fuse and that is why it will only start for 20 seconds and die. And eventually the fuel pump will fail because it is banging around in the fuel tank.

So here is the options they are giving me.

1. They will show me where this fuse is under the hood and give me some extra fuses to fix the problem. ($200.00 for diagnostic and tow) and run it until it happens again. Or I can do options 2 or 3 now.
2. They will replace all the original stuff they replaced with new parts under warranty but if it happens again no warranty on the parts if the same thing happens again. (Still $200.00 for diagnostic and tow).
3. They suggest that I buy a new fuel tank they will cover all the cost of the original stuff they replaced with new for $650.00 that includes the original $200.00 for diagnostic and tow and if anything happen again it is under warranty

Sorry to bore you with the details but I am on the west coast and I am suppose to call them in the morning with what I want to do. Any help or suggestion would be appreciated

Thanks
Brad