Excellent decision! If you plan to study Medicine in the US it helps to have at least 1 year of courses in an American institution, or most of the time they won't even consider your application. About your questions:
- Many institutions offer "official" post-bacc programs. I'm currently enrolled at one in Illinois, where all classes are geared towards completion of Med School requirements and all are in the evenings (so I can continue to work during the day). If you won't have a full-time job, which you probably won't unless you get an H-1 work visa, you'll be here most likely on an F-1 student visa (unless you're married and plan to bring your wife, in which case the visa will be different). A student visa will not allow you to work in the US, only to study, and you have to be a full-time student (12 or more credits per semester). This means that you do not have to limit yourself to an "official" post-bacc program, but you can apply wherever you please, since the vast majority of universities in the US will allow you to enroll to take courses even when you're not working towards a degree. The only advantage of an "official" post-bacc program is that classes are offered at night (most post-baccs like myself are career changers and night classes help) and post-bacc institutions usually have a pre-medical office that can help with advising, etc. However, at this point, you can apply anywhere that will allow you to study pre-med classes without necessarily working towards a degree. Again, I'm assuming you have to come here on an F-1 visa. Only you know if that's the case or not.
- Being an international student is no problem. All you have to do is make sure you work with the Office of International Affairs (or whatever the university will call it) so they can fill out all the necessary federal paperwork so you can get a visa to come to the US to study. Again, I don't know your situation, so I'm assuming you'll be coming alone, which means an F-1 visa and you can't work (only part-time under very specific circumstances).
- Federal financial aid (Stafford loans, Perkins, etc.) are not available to international students. If you want to come to the US to study on a student visa you have to prove you can support yourself for the entire duration of your stay (yes, that means tuition, room, board, etc.). Sorry.
- You should wait until your final grades before you apply to any institution. They will need your final transcripts anyway. Final GPA is no problem; you'll probably be OK (depends on the university you apply to...standards vary).
Some comments on your plans: studying medicine in the US for an international student is super tough! Only a handful of Medical Schools in the US will consider you. Most Med Schools will only consider either US citizens or permanent residents. I'm assuming you're British. Perhaps you're an American in the UK, so this will not be a problem. Also, if you're dead set in enrolling in an "official" post-bacc program, you can check out Medpath. They publish a directory of post-bacc programs in the US. By the way, the reason I refer to post-bacc programs as "official" (in quotation marks) is because most of the time, post-bacc programs are nothing more than a name. You'll be taking classes with regular freshmen in bio or chemistry, but you won't be working towards a degree. The university will not have a real post-bacc program or department per se. Some, however, will issue special post-bacc completion certificates (which are useless, really. Your transcript is what matters).
Sorry about the length of this message. I'm quite experienced with the whole process of coming to study in the US, since I came to study here 16 years ago on an F-1 student visa (I'm from Spain). Things might have changed a bit, so check with someone who's not as old as I am
Also, my advice is from someone who went through the process a long time ago. I'm not an advisor or a lawyer or anything like that, so check my comments with official sources from the universities you want to apply to just to be sure (you can tell I've lived here long...I have a disclaimer at the end of the message). Good luck!
- Lucho