Hey Will,
I've had my plumbing company for about 6 years and have used BMO the whole time. They've been fine. The majority of my customers pay via cheque so having pavilions where I can cash cheques is important as well as quick access to cash flow....no 5 day holds or anything like that. Also, it's key that they have a well structured online banking system, you may find yourself paying bills online often like..fleet gas cards, company credit cards, suppliers, etc. Anything you can do to limit the time wasted running around is key. Also important to have easy access to your monthly statements so you can forward them to your accountant. Not sure where you're located, but if by chance you're in Edmonton let me know and I can forward my accountants info. He's a numbers wizard and has saved me a lot of $. Took two crappy accountants before finding a good one.
Also look into wave, it's an online accounting system. It saves a lot of headaches. It tracks everything and has templates for invoicing, estimates, bill payment reminders, even allows you to setup customers for online credit card payments....and it's free!