Just throwing this out there in case it's good food for thought.
I have two Eclipse tanks, the 12g one and the 6g one. I hate them. They were our first tanks and they are in storage now. I'd only pull them out if we needed another quarantine tank.
They are awkward to get in and out of and I don't know if it's the lighting or what, but mine seemed to grow algae way more than any other tanks I've kept.
If you'd be open to this idea, you might like it better (I do)... What about a 10g kit (with light, filter and heater) and a divider screen or two? We have 2 10g tanks going with 2 dividers in each (so three compartments) and keep six bettas in them (3 in each tank). It would probably cost about the same or maybe a little less (as the Eclipse system doesn't come with a heater, and the 10g kits do (look and pick one that does if you go this route)).
Another thing I like about this is I can put permanent / non consumable media in the filters on the 10g's, which I couldn't for the Eclipse tanks (couldn't find anything that was the right size). I used some small ReeFresH2O (formerly called Cell Pore) cartridges in the 10g filters. I had to break up a little to make them fit but now the tanks never need new cartridges and have tons of space for good bacteria to live.
Good luck and enjoy whatever you go with
PS this is what we did instead of the Eclipse tanks and the 2.5g mini bows we had previously used: