50g

I am considering a 50g purchase. Has anyone here used the hard
protective shell advertised at
http://www.calculatorsource.com/ob-3000.html

There is a link on that product page to a clear "soft" case which
allows operation while in the case. How would you compare this soft
case to a sealable plastic baggie?

The HP website offers a ROM upgrade to version 92. My OS is Kubuntu
Linux 8.10. Does the supplied "connectivity kit" software work under
Wine? Would you recommend I get an SD card reader/writer for my PC?

is 2 GB the most memory in an SD card that the 50g can handle? Are
there any specific dealers for an SD card that you would recommend?

Is any rechargeable battery pack recommended? Is there a solar powered
recharger which will recharge said battery pack, if one exists?

Has anyone developed a power supply to run off of standard 110V AC for
operation without batteries?

Thanks!