most reliable battery? Well, the A123's are the best of the best but they are expensive but they are incredible. The MIT team used them to create a state-of-the-art electric car. They charge fast and are capable of giving out lots of amps.
Then you got Thundersky, Headway for lifepo4. Then you got some kind of special NIMH. I can't remember the link for that though but I think they went bankrupt because they didn't deliver on their promises and the batteries were no good. Also, you have LIPO and hobbyking.com for those.
As far as e-bikes and motors. The A2B's are ready built bikes that are pretty good but I don't think they are made anymore but you can do a search for them. They were pretty good bikes and were very convenient as the batteries were built inside the bikes steel tubes. Then there is eplusplus electric bikes which have a kit that goes for about $2000 and they build the batteries inside the rims and it's a pretty good bike. You can find reviews for that on this forum.
Then you have your usual stuff like nine continent motors, crystalyte motors, BMC, heinzmann, bafang, etc etc.
If you want a good motor for the value, I would go with one of the new crystalyte motors. Crystalyte has come out with a brand new motor that is ultra quiet and very powerful. I have one of the older ones and it's awesome. Very powerful. Very quiet. I recommend crystalyte. You can find crystalyte stuff if you just google it. Ebikes.ca has some crystalyte motors but they may not have the newer ones so check !!! and make sure you are getting the new motor and not the older one. I think the newer models are called like HS5000 or something like they have a code system....I think it's like HS5000 where HS is "high speed" and then they got a HT5000 or something where it stands for "high torque". Look for that. If it's like 5303 or a phoenix racer, those are the old models.