Spooky you asked about the IBU2 , It is a control board but it is infinitely superior to the RX18 and at £120+ you would rightly expect it to be.
In the UK it can be purchased from -
www.rctankelectronics.com
The guy to talk to is IAN and his service is top quality unfortunately there is a downside, he is from MANCHESTER!! I hope you are alright with that.?
Shaun.