Credit unoins offer more flexible terms if you have an account with one but more inportant shop around. There's no easy solution to your problem unless someone here has done the shopping around bit already. Why not apply to all and see who gives the best results.
Some CU's may offer competitive loan rates but it's often hard to get an accurate APR quoted since many also require you to keep money on deposit at the same time. Chances are you only have the choice of one or two CUs with which you have a "common bond" (e.g. neighbourhood CU, work CU etc.) so no harm in checking them out when shopping around.
On the offchance that your mortgage (if you have one) is with the EBS check their rates as they do a special rate for mortgage customers which when I used it last year was nearly half the best normal lending rate elsewhere.