This is from YEARS ago and might not be relevant anymore but I can remember one of the big reasons for the in-tank fuel pumps was to keep the pump cooler since overheating an external pump was a problem. I have no idea if they've come out with better pumps now or if they run cooler than they used to.
I'd really debated on mine as to which way I was going to go. And at one point was going to pick up this used fuel cell but they seller flaked out on me. Since I've only really got two runs with the Jeep I can't comment as to how much I'm draggin my ass yet.
I think as long as the pump isn't close to the exhaust there shouldn't be any issues, at least with the pump I have. I'm mounted underneath on the drivers side with their rubber mounting feet to keep things quiet. I was dragging the skid more than I would like and that's with a 5" stretch and 40s. I never got stuck because of the tank though.
