I would tend to think that the one day a week pull out option is the one offered because that is what your particular school can offer. Since the full time gifted program is not at their school they can't offer that as a recommendation. (They don't have that option in Fl.) I would guess that if you ask them about switching schools to the full time program they may say that it would probably serve his needs better. However, they can't put it in writing because the IEP is supposed to be based on what they can offer at their particular school. Since these are looked at by the state and as such are legal documents and affect funding, if they say he requires full time gifted and they don't provide it they can lose funding for all IEP kids.
We had some similar conversations with our school (also in FL) when we had our meeting for DD and the woman in charge of writing the ieps said the state is very specific about the wording each school can put on their forms - if it is put on the form, it must be followed at the school the iep was written at. I know that FL allows school choice, so I would put in for a zoning exemption and transfer him to the full-time program with the reason being that it is not offered at his zoned school. They may say that you need to have it in writing that he needs full time programming, so then you go back to your school and ask them to write a letter to the county explaining that he would need it. This gives them a way to help you without putting their funding in jeopardy by saying it is being provided.

good luck!