I responded to similar questions
here (PC specifically) and
here (applying while abroad). To add a bit more...
Transcripts -- I had to rely on help from parents to send in requests as even schools that have online transcript requests will not accept the AMCAS coversheets through the online system, it must but sent snail mail (at least the 5 transcripts I was dealing with). If you are gonna send from Africa, make sure Benin's mail system is secure and bring your checkbook. (and send WAY early). Unless your PC country director says that the mail system is good, I would strongly discourage this route. Maybe PC helps their volunteers send mail to the US? Or look for other foreigners traveling to the US when you need to mail stuff who would be willing to take some envelopes for you to stick in the mailbox when they land in the states. A lot of people on my local ex-pat list serve utilize and provide such favors.
Interviews -- this is the hardest part. I imagine flights from Benin to the US are generally a lot more expensive than from where I am in Latin America (still here til august!). Trying to group interviews together is difficult, but doable. I got interview invites from like 15 schools as I recall. Schools would generally let me postpone my interview date, but even the postponed date did not always coincide with other interviews I'd already scheduled (schools often open up slots in a block fashion, so you can't always just choose any later date you want). I had to start planning an interview trip for VERY late in the season (end of Feb) as a last option to schedule interviews that I couldn't plan around an earlier trip. This could put you at quite a disadvantage at some schools. In my case I felt that I had a very strong app and was willing to put off interviews a bit. Not everyone will want to do this, but as a PCV you have a big plus on your app/resume so I bet you'll be ok. In the end I planned 4 different trips to the U.S. (Oct, Dec, Jan, Feb/March) but after the first two of these trips and three interviews (at my top 3 schools, first trip was already planned to attend a conference) I got an acceptance and withdrew the rest of my apps. (I knew I wasn't gonna get need based aid and didn't like any of my state schools, so I didn't have financial aid stuff to worry about in my decision making).
I had heard of students emailing schools they hadn't heard from yet about interviews and letting them know they planned to be in the area for another interview on such-and-such date, to see if they'd get the invite for that time. I tried this a number of times (email to admissions) and had no success. But I think it might work at some schools, as I recall hearing from others.
All this being said, why don't you want to apply the year you get back from PC? Returned PCV are a hot commodity so you should no have trouble finding an interesting job for the year, and that will further add to your application and strength as an applicant. Spending time abroad is a great opportunity for someone planning a career in medicine, but taking the time in your own country to reflect on and learn from that experience--put it in your own local context--before jumping into the intensity of medical school, is very important as well. If you are class of 2010 you have plenty of time to go to med school and be a doctor! (check out the non-traditional student forum on SDN! I'm 29 and starting in this fall...) Your PC experience will no doubt give you tons of material (experiences, insights, passion!) for your app, PS and interviews... and I think having the full two year experience will be far better, as well as the time afterward in the U.S. There's no rush, everything you do (particularly for PC types) before medical school is preparation for being a doctor, even if not clinical. That's my two cents at least...
🙂
best of luck!