I've recently started to consider converting an older steel framed (and steel fork), non-suspended 26" mountain bike to an electric bike.

I do a lot of bike riding but have never ridden an electric bike. I think I'm looking for electric assist (as opposed to fully electric powered).

I've seen that there are front and rear wheel hub motors. What are the advantages/disadvantages of each?

I've done a lot of wrenching on my bikes and on cars. Is there some consensus on what is the best kit?

On batteries, I'm assuming that Lead-Acid is cheapest but also heaviest. Are there any other considerations?

Thanks!