In generaly, the higher the mAh (milliamp hours) rating of a battery the longer it will last from fully charged.  However, when tested batteries show quite large differences and there isn't always a strict correlation between how long they last and their mAh rating.

The 2300mAh Uniross ones I got are the bog standard ones that you can get in Dixons (or Argos I guess).  Mine came with a charger.

I use a 256Mb Lexar CF card.  I've no idea what they cost now other than they're bound to be a lot cheaper than when I bought mine!  btw, don't splash out for an ultra fast CF card, the regular ones will be fine as with the E-10 the limiting factor is the E-10, not the card speed.

Michael.