500-600# machine? I've never seen a restaurant with anything less than 900#. Still more typical to see a 1300# or a 1600#, or even 2400#, but obviously some restaurants are bigger than others. I'd get the absolute biggest machine you can fit, remote of course.
Hoshizaki is a great ice machine, Manitowoc also a good choice.
Also, just to let you know, I'd say 75% of the time somebody tells me a Hoshi water pump failed, it actually just had a broken piece of the cube guide stuck in the impeller Take it apart, remove debris, and magically it works again! Of course I've seen a few failures too, but not very often.