I can't exactly say, because I've not be please with anything I've used to date. However, some of my friends rave about these Thomastik-Infeld set that are on sale now. They are pretty expensive regularly priced, which is why I've not tried them yet, but this sale price looks good. May be time for me to order. Let me know if you do find something you like, I'm still looking. BTW - I've got the Godin 5th Avenue too, and it really is a nice guitar.
You might try Everly strings. I find them a little darker than the DR strings that I normally use.
There is no way anyone is going to be able to tell which strings to buy for your Godin firstly because we do not have your ears and also every Godin 5th Ave. is not going to be like any other in terms of sound.
You are going to do what every musician has to do experimenmt continously with differnt model of strings and even then strings always change up to one day you mlike them and the next day hate them ( living by the ocean can give good days and bad days )
Here is some reading for you, but please do so with a grain of salt and make your own decision.