Ah, wonderful wonderful! At least you've got some experience under your belt and have an idea what you've gotten into....I always worry and am always hesitant when I see anything involving bettas and science experiments...you wouldn't believe the number of people who do that kind of thing without any sort of forethought about what they are going to do with this little living creature and end up having to deal with putting much more money down on setups, heaters, the works then they originally planned. Not thats its their fault of course, we live in a society that pins fish, especially bettas, as easy and disposable pets....but as I'm sure you can understand, its always a sad thing to see.
But, with that said, you of course care about these little guys quite a bit and seem to have the right idea about what you're doing(hey, anything that proves and educates others on why bettas shouldn't be kept in tiny little bowls is more then awesome in my book!)and you've got some great sounding future plans going on; these fish are going to be in paradise soon I'm sure! xD
There is a TON of great info and resources here on the forum. If you haven't stumbled across it already, this sticky organizes links to all the different stickies resources on the forum; lots of stuff about cycling and water chemistry if you still need a little help!
The 'Planted Betta Tank' section of the forum here is also fantastic for whenever you want to look into that; we lots of wonderful and experienced members in that area who know all kinds of stuff about live plants and naturally planted tanks!
A helpful tip about the dividers and the divided tanks though....
Totally up to you if you still want to eventually get them all separate setups, absolutely your choice, but for the moment or for however long you may need to keep them divided, after keeping divided tanks for several years I've found a method that seems to be quite effective and hardly at all stressful.
For my dividers, I use this as a base: http://www.tropicalfishkeeping.com/d...ividers-21866/
as a craft mesh, homemade divider I've found to be much MUCH cheaper and more stable then anything you'll find pre-made in stores, but I have made a few modifications of my own over the years. What I do is double up on the craft mesh(they make it in different colors by the way....I use primarily black or white, though they have purple ;) )and do a little more exact measuring and cutting so that the divider fits a little more snugly without quite so much of a bend. After I started doubling up on the craft mesh, not only did my dividers seem more stable, but I had far less divider mishaps and I noticed that my boys very rarely seemed to catch glimpses of each other...I think they are all aware there is something on the other side, but none seem to pay hardly any attention to their tank mate(s), even when bringing new fish home I would notice much less flaring and posturing from them in this sort of divided tank initially, if any at all, and none after a few days.
So if you're worried about them stressing a little over seeing one another, I think thats the best way to go with dividing. Of course most will get used to one another eventually otherwise, but IME this method seems to work the best in general with most fish and a variety of personalities.