Saris, Thule, Yakima. You didn't mention what "affordable" means for you but you're probably looking at between $500 to $1,000 for any of the three. With the right fit kit hardware they'll fit securely with no drilling required.

Of the three, I prefer Thule but that's because I have a lot more experience with Thule than either of the other brands.

If you have a garage, put your opener in the glove compartment when you load your bikes onto the roof.