I love the Kontronik Beat ESC's! I'd go with either a Beat 40-6-18 or a Beat 55-6-18 for the Eco 8. The latter one being the better choice since it can withstand higher currents. I've also heard good things about the 45Ho.. I'm just not familiar with it.
I'm also planning on putting my Jeti/Phasor combo back into one of my e-planes where it works best, not that it's bad for the Eco but I want more. As far as motor is concerned, I'd definitely go with a HACKER. Snoop around Tohru's website and choose the one that suits your needs.
What kind of connectors are you using between the ESC and battery. Also, what charger are you using?
I'm using Sermos connectors. They work great!! All you need is minimal soldering experience to install them. I haven't tried any other brand of connectors since I'd have to switch ALL my R/C stuff (cars, planes, helis, chargers.. etc). The sermos are good enough.
As far as the charger, I'm using an AstroFlight 112D to charger my stuff. It's a really good charger, but I'm sure that there are better ones out there. It can charge from 2 to 40 cells which is great. But it doesn't discharge..
. It's also DC/DC so I had to purchase a 12V converter (is that the name?) to be able to charge from a regular house outlet.
Let us know which motor you are looking at.