No, you won't be able to get OTA updates after rooting, but why would you?
Most custom ROMs have higher versions of the Android OS than stock - CM7 has Android 2.3.7, the latest stock is only 2.3.5. Also by rooting the phone you will be able to solve the biggest problem this phone suffers from - the seriously low memory.
As for whether your phone is compatible with the rooting guide, it will depend on whether it is GSM or not. GSM phones have sim cards, so if yours has a removable sim card, you are good to go.
Meteor is just the carrier and this does not affect the rooting process at all.