Angela, the first question is how much water do you use per watering? For a couple dozen plants, most counter-top systems are OK, but for a larger collection, a regular residential or growers system is a better choice.
One way to do assess your water demand is to use your watering hose and time how long it takes to fill a 5-gallon bucket. Estimate the total time and calculate the total gallons. That will help determine the system and probably more importantly, the needed RO water storage capacity.
I've been using RO systems for over 30 years, and have been building and selling them for 25. Rather than a huge thread covering this, how about just giving me a call and we can discuss it. Check your PM.