I'm certainly no expert, but installing an RO/DI is no big deal.
You can put it anywhere you have space and a sink. You don't even need to permenantly mount it if space is an issue, just drag it out when needed.
If you have a laundry room that might be a good spot. I connected mine to the cold water supply of the washing machine with a Y adaptor. The waste water line either gets put into the washing machine or the laundry tub depending on wether we are doing laundry that day and can use some "free" water or not.
You can also buy a vampire tap (for supply-easy to install) and mount the unit under your kitchen sink. Waste line can just be stuffed down the sink drain when in use and hidden other times.
Can be really easy...
BTW an auto shut off is a good investment, but you'll figure that out on your own
Cheers,
Owen