I´m using Turnigy Nanotech 5000mA, 50c (523g, 38€)
http://www.hobbyking.com/hobbyking/stor ... duct=37497This is the best quality/price I´ve found in my experience. Loading charge measured is 5300mA!. The most important is the "50c" in order to get long runs. A drawback is the "Nanotech", that usually has shorter life than "lipoly" classical. I´m testing a couple of this batteries and after 5 loads, charge droped only to 5200mA: very good for the moment.
I´ve installed already 3xDIMU´s in my 3xboards. Having an even better altitude control, mainly in ALT_HOLD. Anyway altitude with AIMU was already very good in this HEXA. Main reason I guess is the "ultra low" vibrations onboard.
There are several copters under constructions now, some of them already finished. Still wayting the spanish 3DPrint supplier feedback (I fear he underestimated the quantity of work vs price). Lets see...
About central plates is much easy to get. We have several suppliers working well.