I have decided to leave the choice of a garage disposal up to the family plumber. He did not really explain whether a pro line one is better than the regular lines but the pro line Insinkerators are the ones he buys.

Our last GD was a pro line ISE and it did very well by us.

The pro models have longer warranties than the corresponding consumer versions; there is a low-profile near-top-of-the-line model (1000LP) that intrudes less into your cabinet (particularly useful for deep sinks), and the top-line model is a bit more powerful.

Here is a link that might be useful: Insinkerator Pro disposers

Yes, we got the top of the line XL. The 1.1 HP one. It is very quiet.