Hi Alan, I don't know much about bikes, especially the terminology, but I just bought myself a cheap bike and kit and have been fitting it with a friend who knows more than I do. Having said that I am very technical and it's not actually been that difficult to learn. The 8Fun kit is pretty good and has cost about £450 with a new bottom bracket. It worked straight away when installed in terms of the computer, throttle, motor, battery, etc. That was all very straight forward and they all took about 1/2 hour to install, i.e. without tidying the cables straight away. Of course, having removable grips is a good idea, as you might find yourself taking them off a few times. But, for us the pedelec has been more problematic, which is a known issue. There are two main issues: 1) the length of the BB might not allow the sensor wheel to rotate/sense properly, and 2) the bars on the bb (sorry, don't know correct term) might not hold the pedelec sensor wheel so it freely rotates (and might need adapting). I have 3 BBs and two of them have issue 2 and one has issue 1. I've ordered a new, longer one for £6.95 but can't be sure if it'll be ok without adapting it. It'd be ideal if I could take the sensor wheel to a shop and try it.
The 8Fun kit I bought comes with the bottle battery and a front wheel motor. There are a few like this on the market to choose from. Some claiming to be of higher quality. So, I'd look into what differentiates them. But, I just chose the cheapest I could find. I know, not always the best option.
The only other issues we had are:
a) The battery not being held on too well, so we've added a strap, which doesn't look to bad to be honest. This holds it in place well.
b) Tried the wheel on an old Saracen bike and the end of the fork (sorry don't know term) was too wide, causing the motor to rotate and the wire get caught under the fork sheering the surface of wire. Fixed that and ensured the cheap bike we then bought had compatible forks as not all of them are.
Anyway, hope this is of some help.