a. Call or email
Horizon Wireless for a quote.
b. An external charger will do the job, but it's a pain to swap out batteries every day. That will get old real fast! An AT&T store might have them if it's a big enough store, not some independent shop or mall kiosk.
c. The only charger I have seen that uses the side contacts to charge is the [
Blackberry Power Station, and at $99 it's an expensive solution.
d. Getting it fixed is the only thing I'd recommend. If it costs less than $99 to get it done then it's a way better solution than c. Getting back your USB port is a big deal, for usage and for resale. Without the USB port, you can only resell it as junk, for parts.