Dabug,
Since your will be current in May, you will have 4+ months before time runs out at the end of September. I don't know how long the processing times are through the AOS route, but 4+ months sounds like a lot of time. Check the AOS threads for the latest info on that. I also heard that they move faster towards the end, so I'd be very surprised if they didn't get to you by the end of September. Again, follow the AOS threads closely and check out the discussions people had last year to get a sense of how long they take. Not to scare you but I read somewhere in this forum a while back that an F-1 student, who chose to do AOS processing and was denied, eventually got a deportation notice. The positions of the USCIS and the embassies regarding F-1 and DV are rather vague and there's a lot of handwaving in forums all over the web. The most common point that people raise is that F-1 visa is tied to a non-immigrant intent, so DV application can be construed as a clear breach of an important requirement of the F-1 status. My feeling based on the few emails I have exchanged with the embassy in my home country is that what people generally tend to think about the complications of F-1 and DV aren't 100% true. However, I have used the information I have gotten from them merely to get myself to stop worrying too much, and I am still not very clear myself whether my F-1 status will be in jeopardy if in case my petition is denied. The embassy told me my F-1 visa shouldn't be affected, but there may be other issues I have no way of getting clarifications on at this time. For instance, there's the issue of how the Customs agent will handle the case when I try to re-enter after an unsuccessful DV petition.
In short, my advice for a case like yours would be that if your record is clean, and you meet the education and sponsor requirements, there's no need to worry whether you do CP or AOS. What may happen if the interview is unsuccessful can drive you crazy because so much is at stake (especially if you are close to getting your degree) yet there's so little information on this, so you are better off getting that idea out of your mind for now. Just prepare well and you will be fine.