I'd like to get a portable powerpack with Microusb to connect to the N900 and run on replaceable batteries.

I'd also like to get an extra battery or two from amazon.
$26.95

and maybe something like this if made for N900:
http://www.amazon.com/XpressMusic-De...ref=pd_sim_e_3

I haven't decided on what case I want yet.

Nor screen protector, though glare reduction is very important to me and I've heard that the Zagg protectors aren't too great in sunlight?

Any recommendations?