I bought my LaCrosse charger from Thoma Distributing, and was glad I did when I needed to return it. I couldn't get through to LaCrosse customer service, but Thomas took care of me. I've used a variety of NiMH rechargeables, and usually get about 1 hour out of a charge. I usually ride about 30 minutes each way, and recharge when I get home. The Imedions discharge as fast as the rest do, and any NiMIH is going to fade quicker when it gets cold outside. Can't help you with the rest of your questions, but expect you'll be happy with your choices.

I got some "free" plastic battery holders (for the spares) when I ordered my charger. These work great for carrying the spare batteries you'll be glad you have the first time you run out of juice while riding around.