Yeah, when using the WPG rule on CFL's you need to use their actual wattage, not their "equivalent" wattage. a 23w (80w equivelant) is just 23w.
Also, since they are round and about half of their light does not end up in the tank (i don't care how good your reflectors are) they really only count for about 2/3 of their rating so the 23 watters are now 15.5 ea.
For Your 80g tank you need 13 of the 23w bulbs.
My 34 is currently set up this way, I use 8 of the 23w bulbs works great.
IMO you would be a lot better off using 4 foot shoplights with 32w t-8 bulbs in them (3 shoplights for a total of 6 bulbs and 192w (2.4 WPG)
It would be a lot cheaper and more efficient.