fuel cell install

I'm thinking of putting a fuel cell into my '90 coupe. It will be street driven 98% of the time. Looking at a min. of 15 gal. Will modify the trunk floor for a nice clean appearance. Can you guys give me any tips for installing one,I've never put one in. Pics would be a big bonus and help. Thanks

not an actual need,just something different.This being a 20 year old Ontario Canada car, there are a few rust holes in the trunk area. For some reason they like to rust out in the filler neck area. Some of the spare tire well is showing some holes. I thought as long as I'm making up new sheet metal I would reshape the trunk floor for:
A. a fuel cell and battery box
B. keep stock tank and make compartments for some stereo equipment
C. ?
car has no real value,1 of a gazillion 4cyl. Swapping in either a 408 or a BB. Just needed some pointers to help me make up my mind,before I start the new sheet metal work.