you need to approach both of them.. see which works out the best deal and then go by the authentication... make sure u do your research before signing the papers.
neither one is better or worse than the other. It all comes down to the people they have working for them. Shop the interest rate around Shopping for Interest Rates - The Secrets follow the rules at the link provided and you'll do fine.
As much as possible, approach both the bank and a mortgage broker for a home loan.. Familiarize yourself with their terms and from then you can decide for yourself which has great deals and offer.