FWIW, you *CAN* run the RO to the ice maker if you have a very old ice maker. Our ice maker in our work refrigerator is from a 1970 Kelvinator (Fridge is from 1989) and has the fill cam adjustment maxed out and works fine from the RO tank under the sink. Occasionally will have a hollow cube or two, but for the most part works. Having a very long fill time is essential to compensate for the low flow rate due to low pressure.

My house doesn't have an ice maker connection so we use trays. The sink has a 3M filter cartridge connected to a dedicated faucet for drinking water and we use that for filling the ice trays. It produces crystal clear ice with no flavor, so that may be an inexpensive option. You can pick up the 3M kits at Lowes/HD/Wal-Mart for ~$50-60 and the cartridges last a good year or so (they claim 5000 gallons).