How do i switch from IDEN to CDMA (boost mobile)?

how do i switch from iden to cdma and keep my current phone number? currently i have a motorola i465. its an okay phone but i hardly get a signal, i can't text and talk at the same time and i have numerous dropped call. i'm thinking about getting the sanyo incognito, it seems pretty awesome. how do i go about transfering my phone number and everything to the new phone? thank for your help :)