...Try to have the drain lines at the bin, and at the machine, arranged so that you will have easy access to clean them. There's something about melting ice that causes a rapid growth of black slime/mold that will eventually clog the drain lines, (and your plumbing), if not cleaned regularly. A good shot of bleach once a week will help keep the plumbing running freely.
Brady's comments are dead-on. Put the machine in a backroom and put a bin with a drain in your workspace. Try to have the drain lines at the bin, and at the machine, arranged so that you will have easy access to clean them. There's something about melting ice that causes a rapid growth of black slime/mold that will eventually clog the drain lines, (and your plumbing), if not cleaned regularly. A good shot of bleach once a week will help keep the plumbing running freely.
I was a district manager for a fast food corp. for 13 years and thus have had a lot of experience with ice machines. Hoshizaki is definitely one of the best brands, but Scottsman and Manitowac are good too. The half dice size is good and so are the ones that make quarter-moon shapes. Large cube makers are not very common because it takes more time and energy to produce large cubes. The pellet makers I've had were very prone to breakdown due to the pressure required to form the pellet. Definitely stay away from flakers. Every flaker I had would breakdown way too often.
The smaller output commercial machines, (those rated under 250 lbs. per 24 hours), are usually self contained / air cooled. If you have it near your workspace the heat thrown off by the condenser coil will have you sweatin', and the noise will drive you nuts. Larger capacity machines will usually have the condenser and compressor mounted on the roof, thus taking the most of the noise and heat out of your kitchen.
From your description of your anticipated useage I'd think you'll need something over 120 lbs output, but anything over 275 would be overkill. The size of the storage bin is also an important consideration. Sometimes a low output machine with a big bin can suffice in certain situations, (realizing that after your 4 hour rush period it will have 20 hours to refill the bin).
A good water filter with a scale reducer is a very good idea, but nothing will make a machine totally maintenance free. If you're mechanically inclined you can clean the inner workings of the machine yourself. If you're not, plan on having a service person come in a couple of times a year to clean the coils, floats, water distribution channels, ect. It'll save you money and headaches in the long run.
I would look hard at leasing, Ice machines break down... a lot and having someone else be responsible is a nice thing. You should be able to lease one for between $75-150 depending on size, no unexpected repairs, no "emergency" extra repair charges. We own one now but as soon as ours breaks down we'll lease the next one.