>>>I've six wee Sub's, and depending upon what happens, the Killies will either be dithers, targets, or 'ornaments.' I'm hoping the latter... <<<
Actually, depending upon the killie, it's the sub's that may become targets. No kidding. Some Fundulopanchax garneri (GAR) are down right mean, even though they are considered a beginner's killie. Some people have success with mixing them in a community setting while others, with the very same species, have nothing but problems. You can go ahead and experiment, but do so carefully and at your own risk. :-) And be ready to yank one or the other out of the tank. I speak from experience with a lonely heart male GAR in a tank of Lake Tanganykan cichlids!
BTW, The Lineatu (LIN) are not from Africa. They originally were collected from India (and Cylon?). You might want to look for an Epiplatys species for your experiment. They stay near the top and have reasonable dispositions. Or you can try finding some lampeyes. But they will be hard to find and more expensive. They also require very clean, oxegenated water to be successful with them.
Remember, the worse case scenario is that you have to yank them out and put them in a small tank by themselves. Of course by then you'll be hooked, and the only thing worse than a Cichl-idiot is a Killie Nut!
As far as availability, join the killie list and join the AKA. There are plennty of folks to help out and suply fish (via the mail). You can learn more from the AKA web site (www.aka.org). There's also a photo galery of many killies there.
BTW, the AKA National Convention is in St. Louis this memorial day weekend. There will be hundreds of the most colorful little fish displayed in one hotel. If you have never seen a live killie and can get to St. Louis, you will not be disappointed. Just remember to bring a flashlight and plenty of batteries (trust me).