S10 swap & gas tank...

[MMM...BRAINS...]

I'm setting up the bed from my '49 on the S10 frame as well as fitting up the running boards and before I finalize that i started thinking about gas tank location and spare tire. this will be a bagged truck (not laying frame, but pretty damn low)
my first thought was to locate the gas tank under bed behind axle and set up the filler on rear driver fender. Then i started thinking about the spare tire. this will be a daily so i want it functional, not just "cool".
I do not want the spare just sitting in the bed. so i started re-thinking putting the gas tank under bed and utilizing the S10 spare tire location. granted i may have to raise it some as well as the bed floor (i dont want to see anything hanging below the rear of the truck) i'll also prob add a trailer hitch as well back there.

SO, the questions are, where is your gas tank and spare tire? im not planning on a full size spare, just something to get me to a tire shop if need be.
do i keep the origianl '49 tank location (behind seat) or go with the stock S10 tank or find a better place for the spare tire...?

for ideas, i like to see/hear about your set-up.
Thanks,
Chris