HI There
The connectors used by Heng Long are JST-XH connectors. If you do a search on eBay for JST-XH you will find them. However, these connectors are mostly used for LiPo batteries and hence you will find lots of connectors under 6-way. You might find it hard to get a 8-way but they are there.
For a one off job you could get away with crimping the wires with some needle nose pilers and then add a bit of solder. To crimp properly you will need to get a crimper.
http://www.ebay.com/itm/Engineer-PA-21- ... 2a36e143e0I can vouch for the PA-21, I use it all the time. There are some way more expensive crimpers and some cheaper ones.
Cheers
Kevin G