Ohh, this is only the 4rd time trying to post this F$%^*( response, so bear with me, heres a short version;
No one I know of makes a poly swap kit. I think the "LA" mounts would work though. IMO, skip it in favor of a "LA" because of the plentyful over the counter part selection and save money while your at it. Not to mention weight.
The swap to 4spd doesn't make it easier. Just alot of fun once you get it right.
I did this here;
http://www.forabodiesonly.com/mopar/showthread.php?t=10508&page=1&pp=20 Click it and read on.