Nationwide Service?

One idea is to "self-insure" so to speak. By that I mean that you charge your customers a base with overages, etc. just like you would normally but pay the provider on a time-and-parts basis. With 100 units i would think that you would have enough units to cover the risk. You might lose on a unit or two but the profit from the bulk would offset it.

I had a situation where I had a couple dozen MFP's sold just to do scanning but no dealer would touch a maintenance agreement without a minimum print volume. I charged the customer something like $250/yr/unit and some exorbitant cpc in case they did run any copies. When a service call came in, we negotiated a service rate and parts mark-up for that call. It was a win for the customer and it ended up being a huge win for us.

I like the way you are thinking.  The issue for me is all of the copiers are covered on a Xerox cost per print plan.  So, this is essentially a new line of business, starting from scratch.  I have considered buying 4 standardized models and doing an exchange replacement situation.  Where we replace the copier (the client would have a deductible to pay, maybe $300 to cover the transport) - If I bought 5 color copiers at $600 each - Then sold them for say $1900 each - The driving across town would be OK and I could pay a tech to fix a few at a time, rather than single instance repairs.  I might even be able to hire a tech that works for another dealer in their evening hours as I would not be freaked out about a device going down because I would always have some spare units.  If a unit got too expensive to fix, it would become a parts machine.  I am just thinking out loud here.  There is always a way to do things if we are willing to think it through...  

A lot of pitfalls here. I'll list them in no particular order:

After hours service can only work with a small percentage of customers and a tech of ours who worked after hours with a competitor (which you would be) would be fired on the spot.

You may be capable on a relatively current set of models but what happens when those models are no longer a viable option? How can you possibly maintain a competency as new models come out?

I assume you have a source for parts and supplies. Do you have the space and money to maintain an inventory? You can't afford to overnight everything and your customer won't put up with it.

Where are your leads going to come from? Do you plan on doing all the invoicing, and collections, and purchasing, and shipping or delivery of supplies as well as prospecting? I'm quite certain your prospecting time will dwindle to nothing long before you have a minimum revenue stream coming in.

Your best bet is to take over contracts on competitors machines in the field and I would start with a school district or small hospital...someone having to get by on an annually decreasing budget. If you can land an account with 15-20 machines to jump start your business, your chances of success go up significantly. However, I would still rate your chances pretty small.