This was one of the main reasons I went with DMM, they offered motors that bolted directly to my Biesse Rover that is made in Italy. The bolt patterns for the DMM motors were the exact bolt pattern diameter on this machine. Also, the motor shaft sizes were the same as the old motor pulleys and gears. Everything bolted up and fit perfectly. I just had to decide between the DYN4 and the new DYN5 drive. There's a good jump in price but I decided to try the newest technology.
For the record I did contact Clearpath as I thought about going that route but they couldn't offer me direct bolt on motors. I had enough on my "retrofit plate" without having to worry about adaptor plates for motors and pulleys that wouldn't fit.
If Slodat and others are telling you that the motors work great, and have been for 3 years, why doubt this logic and just wire the drives to the DB25? Seems like a very simple solution to me.
I'm headed up to the shop shortly and we'll see if the DYN5 drive loses steps on the Acorn headers or not. I'll let you know.