This guy is really superb and I am very happy with my newly revamped bike, I wanted to share my experience with you.
I purchased an electric bike conversion kit from an Australian business called Solar Bike It is absolutely fantastic.
I purchased the 350W front hub kit with 36V 10ah LiFePO4 battery for my mountain bike (26" rim). I'm getting a range of about 42km with light pedalling and am moving at an average speed of between 35-40km/hr even uphill.
These guys are fantastic, quick to respond to emails and at a really fair price. I think that they've done their homework on all the testing from their responses and website.
Check them out at Solar Powered Electric Bikes (http://solarbike.com.au/conversion_kits.php) They deliver to anywhere in the world.