Pulling the trigger..help me decide!!

OK! Finally back and ready to buy my new motor! Here is my question...

I have a 1648 with decks on front and back! Just got a minn kota terrova us2/ipilot 80lb 24v 45'' shaft that I am pumped about!! The spot lock is amazing!!!

This will require an extra battery up front under casting deck. So basically 1648 with 2 batteries up front, one in back for cranking motor, plus gas tank and motor on back! All decks are built out of aluminum and it will be tiller steer so no console!

I dont care about being the fastest boat, and I RARELY fish more than myself and one other person...
I have narrowed it down to Mercury outboard for resale purpose and I really want the shift in tiller handle feature!


So here is the question....

I can get:
20eh for $2715 plus shipping ($80)

25eh for $3340 plus shipping ($90)

Is the extra 5 hp and maybe 2-3mph worth $625?? What about pt/pt? Which one would you get? Here is a pic of my boat as of now, with old trolling motor, as I have not mounted new one yet...

The EH is a 4-stroke, correct? If so, a tohatsu powerhead. I do like nissan/tohatsu 2-strokes.

I think you are going to want the extra 5hp. I just test drove my new to me DMI 1648 with Merc 25hp 2 stoke. I got a solid 26mph gps with 430lbs of people. I am going to try to keep the weight of my mods down as best as I can, but will be happy to keep wot in low 20's. All those batteries, trolling motor, decks, support, and gear really add up. You probably have the equivelent weight of 1-2 persons already.

PS: this is my 1st merc outboard, and that shift in the throttle is not what I'm use to. I didn't see, but also didn't read the manual, a "warm-up" switch equivelent (rev in neutral). While it has a large knob for mixture adjustment, not sure how well it will work for my cold weather fishing.