Nice looking boat you've got there. Explain to her or let her see this, that a brushless motor is cheaper in the long run. You won't be out buying a new brushed motor every few months, replacing brushes, getting your commutator turned and a lot less maintenance so that you can spend more time with her! OK, sometimes the last one doesn't work too well but it's a shot! The prices are really dropping now with the new Novak that just came out.
Peter from Climate ought to be able to help you if she still doesn't buy what I put above.
Check out his hardware also, he should carry just what the boat needs!