im sure you can get some a custom gear ratio made up for whatever you want but that will cost more money than its worth.
the n/a diff. has a very nice gear ratio...just stick wth that.
as for custom driveshafts...im getting one made by
http://www.z1motorsports.com i am getting this one because i want the full steel 1 piece driveshaft they offer so i will never have to worry about it snapping in half through my floorboard or the carrier bearing going out. plus it is relatively cheap at $250 a pop last time i checked. there are a few other companies that offer this almost identical driveshaft at the same prices. just look in the sticky's for a lost of Z stores...
but im sure a local shop could customize your existing driveshaft to fit your needs for alot cheaper. just a matter of what you want...
is your 2+2 an automatic or 5-speed??? if you are doing an auto to 5-speed swap, i recommend starting with the parts for your 5-speed conversion. some of the parts to swap out your auto for a manual are hard to find at a decent price. z1motorsports also offers a full 5-speed conversion kit but i think it is quite overpriced...
always remember, ordering a front clip will save you a lot of time and headache in the long run when it comes to finding parts. but if you can find the parts that you need and piece everything together yourself, it can possibly save you quite a bit of money and you may end up with alot better parts...
good luck!!! if you have any questions, feel free to ask. i am undergoing the same swap you are wanting to do...