Aquarium advice?

Since the aquarium and salt water fish were brought up, it reminded me that I have been wanting to ask about keeping fish.

I want a tank so bad !!! I've been reading and researching. I'd like freshwater, but my well water has been tested and has way to much lime. It was recommended by two BIG fish stores to get a reverse osmosis filter for the house before I even think about a tank. Then I start with that and add in the minerals/ph/etc. Or, take water home from my work to use (city water) and then test it and go from there.

I've saved and have a couple other jobs for the plumber and am about ready to order the filter for the house and call the plumber in. I also have about $500 saved for a tank (know I will need more).... but I don't know if I can handle one. All the water changes and upkeep have kept me from making the final decision. I think I would like a planted tank. That means getting CO2. I've joined a couple online message boards and they have been a real education. I've gone to all the BIG fish stores within 150 miles. Made lists of fish I liked - looked up which ones can go with which etc. Gone to zoos and public aquariums too. Tried to do all my research.

Here's the issue.... I have a problem now in my non-dominant arm/shoulder that may be permanent. 6 months ago, I could not use it at all... but now I have about 60% of the range of motion in it, but only about 50% strength. I'm still working with it.... but it may be as good as it gets. It's very painful all the time. I have no clue how I am going to deal with my outdoor garden....I may end up giving away or selling most of the plants - that's one reason I am interested in a planted aquarium. Since I could be dealing with the tank one handed - it's been suggested I go for a 55 or 90 because they are long and not very deep. And, an under the tank canister filter. And, a 15 or 20 gal. hospital/quaranteen tank.

My biggest doubt is can I really deal with the fish if I take a down turn and cannot use the bad arm much at all?

Anyone with a tank willing to give me advice on this??

Thanks!