040 are designed to be intank.
I thought the only differance btw 044 and 040 was 044=external and 040=internal.
Just some advise, something learnt by experience. Buy the 040, build a surge tank a little bigger, and mount the 040 inside the surge tank. This will help reduce the noise from the pump (and trust me a 044/040 is bloody noisy), you can then put as much sound damping material, as you prefer, all over the surge tank to reduce the noise even more. Fuel will also act as a coolant for the pump. With a 044 (external) you are unable to dampen the noise as you run a risk of overheating the pump (so i have been told).
I unfortunately just have to live with it, but i honesty am not bothered by the noise, my mates on the other hand can't get over it, and keep biatching.