below deck fuel tank need help!

[evknot0127]

i recently removed my below deck fuel tank because it had aquired water in it somehow. Since i already have it out i would like to just replace it to avoid future problems with it. I went and bought a new poly tank from moeller cuz i thought it would fit and it does perfectly but the fill on it is to high. the tank i took out i believe was custom made cuz it was an alluminum one and the fill is welded on but out on like a 45 not straight up off the tank. what tanks are the best? stainless steel or alluminum? or the new poly tanks? is there a way to customize the poly tank i bought in order to make the fill not as tall? i could have a new tank made up for me at work the same exact size as the original i pulled out but should i make it out of alluminum or stainless?? help please