Batboard

Is it possible to get the radio to the 900mhz band ?

Likely not, since the 800MHz radio band tops out at 869...quite far from where you want to go. However, since this is a Motorola forum, you're likely better off asking at somewhere with a focus on other radio manufacturers, like:

http://www.radioinfoboard.com/

Why don't you get a 900 johnson 5100?