Hey Guys and Gals, Just got a brand new War Eagle 542 boat...I have a Merc 25 2 stroke on the back...Can't wait to get it on the water...

Just one thing...What size shaft do I need for a powerdrive trolling motor? I thought I would go with a PD because they are lighter than a traditional foot control, like an edge, and I could run the boat from the back...If I got a 48" PD shaft I thought I'd have a warranty center for minn kota shorten it down so it would not be so long...Maybe 42" or even 36"...I definately won't need a 48"...
Thanks for your help...