E Bikes are very popular abroad and I noticed a lot of locals used them in the Alps. However, they are cycling downhill, doing their shopping in town and using the motor to get back up. Then they plug it in again.
E Bikes are really motor assisted cycles and the more you use the motor, the quicker the battery drains. The more powerful the motor and the bigger the battery, the further you can travel but, the bike also becomes heavier when you pedal alone. Speed is also a factor, using the battery to drive the motor at high speeds drains it very quickly. As an indication, with a 300kh battery you will get a range of 40km to 100km on the flat, depending on speed.
Batteries are the expensive item. Not only do you need capacity, but you also want a quick charging time. Some can take 10 hours to recharge. I have a torqeedo electric outboard engine and a spare battery is £400. I can but a cheap engine and a camping battery for less than that.
Have a look at this list of e-bikes from a supplier in Germany. These are proper bikes adapted for electric motors sold into a market that is becoming discerning about electric bikes. These are all well above £1000. If you are wanting to do some distance and rely on the battery a lot, you are likely going to be disappointed with a sub £1000 bike.
http://www.bike-discount.de/en/ebike-trekking
Alternatively, if you want somthing very futuristic and special, you can get a specially designed electric bike from Mercedes, currently reduced from £2500 to £1800
On the continent, there are loads of places to hire these things. I have never looked in the UK though. There ought to be some places. That way, you can get a feel for how useful they would be.
There are lots of reviews on youtube. Have a look at this one which shows different types:
You may also like to read this article,
http://www.bike-eu.com/Shows-Events...ng-Going-Ballistic-at-Eurobike-2014-1579376W/