The big thing you are missing is, in-line fuel pumps need to be gravity fed, which means they need to be below the level of the fuel. So, my suggestion to you is to put it along the bottom of the car where the fuel lines are running already. Just "splice" it in to where the line is and securely mount it. The good thing here is, I believe this still meets your criteria of being able to do a roadside fix, because you can put it somewhere you can still get to it. Maybe not as easily as you could in the engine compartment, but still, easy enough (much better than dropping the tank) to do it along the roadside.
There are MANY aftermarket options which will accomplish this for you. They mainly come from the performance industry, but they work just fine. If you go this route, most manufacturers suggest you put an inline fuel filter before the pump (pre-filter) and one inline fuel filter after the pump (post-filter). The pre- protects your pump. The post- protects your injectors and everything else.
As far as inside the tank when you pull the old pump, all you need to do is pull the pump itself, leaving the rest of the pump housing behind. Then get new fuel line (make sure it is ethanol safe everywhere - inside and out) and cut you a length which will go to the bottom of the fuel pump housing where the sock from the original pump would sit. Once you have it located, you'll need to secure it to the housing. I'd suggest using a jubilee (worm gear type) clamp and probably put some holes in the housing to run it through. This should keep it in place without putting foreign matter (weights) inside the tank.
Most fuel level senders are on the housing as well, so another reason why you'll want to leave the housing in place.
You'll also need to extend the wiring from the old fuel pump location to the new location. You'll probably want to get wiring of a higher thickness than original, just to be on the safe side and not cause any issues. You'll also need to be sure which wires you're taking, because usually the fuel level sender wiring is co-located with the pump wiring. Quite often they even share a ground, so be cognizant of these things or you'll need to start counting miles and hoping you're always getting the same fuel mileage.