Should work. If you can get the guts out of the shoplite in one piece so much the better. I did that and reinserted the guts in an old 36" 2-tube fixture which I installed in a homebuilt wood canopy for my 40 breeder. I added a reflector (angled roof flashing) and it's been working fine. Any amount of overdriving is minor IMHO ...I'd had T10 lamps in it for 3 years or so, and they are just now showing signs of wearing out.
I will have another 36" fixture available soon if you want it.. It's the one with the lamps on the sides of the fixture, rather than the bottom. Your shoplite guts should fit fine.