Join Date: Jul 2003
Location: Charlotte, NC, USA.
You just mentioned a 3 gallon bowl. You could get a 2.5 or a 5.5 gallon tank - a standard size. Eclipse makes several small sizes as well. Some have lights, some don't and generally the lighting is weak. You listed slower growing plants, so it shouldn't be a problem with less lighting.
Nano cubes come in a 6 gallon version, I think. Look through this nano forum and see what people are doing. While it's a little bigger than you thought about initially, I think the 7 gallon bowfront tanks are very, very slick.
You have several options, look through here to see how some others figured out a solution to their nano tanks. I see several topics on the front page for 1.25, 5.5 and 6 gallon tanks. Look around and see if something strikes your fancy.
You can still do a 3 gallon bowl and you can do it well, but a cube tank may be more space efficient for the same gallonage (squares fit better with other squares than a round tank would, but you know your constraints better than any of us).