1970 20' potter - rebuild max engine weight

[Gaud]

i am finishing up my 20' sea craft and now have to re power it.

I re did the transom and raised it to 25". I did NOT raise the floor.

what would you guys suggest as the max weight to have back there?

i am considering the mercury 150hp 4 stroke which is the lightest in its class.

a few friends are trying to convince me to go with a bigger 200 2 stroke.

thoughts?

thank you!!!