Personally I think it would be butt ugly to have light s hanging out that much, plus you are losing 1/4 or the light.
You can try 3 - 2x36 T12 shoplights - here in Canada, Canadian tires has them for about 20 each (HD
about 35). The ones I've seen are fairly narrow (about 4") so you can prob fit 3 into the canopy. They are 48" long so you'll need to stagger them for more even coverage.
Failing that, you can try a mix of 4' T12 & 2' T8 (have never seen 2' T12).
Also check out PC
kits from www.ahsupply.com
- they are suprisingly affordable.