For the GI Bill, only a small amount of the money can be used toward "time building". The money can be used for ratings, but ou are on your own for time building.

PSA's program is much cheaper, first of all. The hourly flight cost is much less, and will save thousands of dollars. Also, you are able to use your new hire bonus to offset any training costs before you are even hired at PSA. This way, you can save your GI Bill benefits for something that is much more cost effective.

If you want to get all 250 hours and not pay a dime out of pocket and not use your GI Bill, you can just use your new hire bonus.