If your looking for an RO, price around. ROs are ROs. It doesn't matter what the name is on the housing. Look for something at least 75 gallon per day, and not "quick change filters".
In Toronto I recommend checking with your local Water Depot. Ask for the "old style" the new quick change ROs have serious flow restrictions and quality issues. If you are looking for DI you wont find that at a water treatment place. As much as I hate Home Depot (the hardware store) they may also be able to order a lower quality system. Just remember that the lower the price, the lower the quality. If you have a plumber you like, (s)he can order from their supplier too. The best pieces of advice I can offer you is to price around, and go with the "sump style" (not quick change) RO system. Take a look at my RO add in the dry goods section to see what I mean regarding "sump style". Quick change filters are sealed disposable cartridges that are usually vendor specific.