Triumph and KTM.
Not going to make a lot of money, but I think Triumph would bring in a good, non-traditional street segment and KTM would bring in the serious off-road and supermoto folks.

But whatever the lineup is, hire knowledgeable people! Guys who ride and know bikes. Put a couple of old retired farts on the payroll who know the answer to old bike questions, and some really smart young riders that can talk bike as well as they can ride! And that's just the sales staff! Make sure the service guys like to ride as much as wrench, and won't be docked for giving free advice! Parts guys who ride every day and know parts! The kind of shop where the sales staff could go find the parts and wrench if they had to, and the parts staff could jump in and help the service guy on a busy day!

And the Manager would take the time to have a cup of coffee and talk motorcycles with everyone who comes in the door (while he's helping out the sales, parts, and service guys/gals)!

I know, I'm dreamin'