I had the same problem when I had older Mc amps and found the best way to get my MITs connected was to get adapters. You can readily find a couple different types on Ebay. I use the 1/4" spade to bananas - works great.
About your gain question: the lower impedance tap will get less voltage out of the amp so yes, the gain would appear to be lower. Try both taps and see what you like best.
You made a great choice on your amp. Arthur
About your gain question: the lower impedance tap will get less voltage out of the amp so yes, the gain would appear to be lower. Try both taps and see what you like best.
You made a great choice on your amp. Arthur