This article may help on length....
https://www.minnkotamotors.com/Support/FAQs/FAQ-Details/What-about-shaft-length-selection-/
As far as "space taken up"...I've recently had two configurations. The "old" one had a trolling motor bracket added alongside the port (left) side. The bracket was 7 inches wide, and the motor used up that length all along the port side of the bow deck.
This was on a semi-V Lowe.
The newer configuration, which was put on by a dealer on my new hull, has the point of the TM right on the point of the semi-V bow. He angled the TM back and something more than 45 degrees, so that the stern end of the tM just slightly protrudes over the port edge. The mount is still 7 inches wide, but cuts a bigger angular swath across the bow.
Actually, I preferred the port side mount better than the "on the point of the bow" mount. The "on the point" mount cut off my ability to place my bow light socket in the middle. Pulling the cord to raise my TM is at a severe angle, too.
I don't notice any efficiency gains or losses with either mount.
Just a testimony as to why I am far better off to do these things myself. Someone else's judgment may not agree with your/my judgment.
I'd suggest making a cardboard cutout the size of your TM's base and taping it in various positions to see what you like best.
regards, richg99
