The first thing you need to if you haven't already is go shoot a newer bow with a release. Just go to your local proshop and tell them you are thinking of making the switch. They should oblige you. Switching to a release and a short ata bow is going to really change how you anchor and hold your bow at full draw compared to your old one shooting fingers. And normally shorter bows are less forgiving than longer ones, not the other way around.
To be honest the bow you have already is a very forgiving accurate platform, just not very effecient. Don't expect to shoot a new short bow with agressive cams better. At least not from the start any way. Then again you may shoot better with a more solid back wall. The key thing is to get the draw length right. Make sure your new bow fits you. If it means taking it back and getting the draw length adjusted again, then do it. However keep in mind it's going to feel wierd at first and take some getting used to.
Could you do it in a month, I don't know, depends on how good you are to begin with and how dedicated you are. It's going to require practice and patients that's for sure. I am not familiar with the rest you have, but keep in mind a rest set up for finger shooting is not the same as a rest for release shooters. With fingers the arrow bends from side to side, and with a release the arrow bends up and down. I think I know what rest you are talking about though and it should work nicely. And if you are going that short of an axle to axle bow and your draw length is near or over 28 inches I highly suggest looking hard at using a string loop. There is a lot of string angle with those short bows at longer draw lengths. And you may not be able to touch your nose to the string either without bending your head down.
I say shoot some different bows of different sizes to see what you like or feels best. Don't go in the shop thinking of particular bow, keep an open mind. I don't know how much money you want to spend but here are a few affordable suggestions. Either the Hoyt ultrasport or ultramag. I shot them recently and they were very nice bows, even at under 400 bucks. Also the parker hunter mag is a really nice bow for the money. And neither one of them is really short either. There are also bows from Darton, Proline and PSE in those price ranges that are nice as well. I however recently purchased a Bowtech Mighty Might and am very happy with it.
Here is a link to get you started if you want to do some reading.
http://www.huntersfriend.com/bowselection.htm
Good luck,
Paul