It's a low mileage car - 86k miles on it

I found this site initially when my Check Engine light alerted me to a possible Trans problem. I was hoping to avoid a Trans replacement by changing fluid hoping it would solve my problem - but after disconnecting the battery and resetting the check engine light - it again came on today - and a quick trip to Auto Zone - still having Trans problems.

I've got 3 codes

1) P0700
Definition : Automatic Trasmission Fault
Probable Cause
001 - Indicates trans fault - check other codes

2) P1164
Definition - Primary H02S ( no 1 ) circuit range / performance
Probable Cause
001 - Open or short circuit condition
002 - Poor electrical connection
003 - Failed H02S ( Heated Oxyben Sensor )

3) P1739
Definition - Automatic Transmission Concerns

This problem has been around for 2 weeks now - I'm driving my car as little as possible - but I think it's something I need to resolve in a timely manner so I can go back to having a reliable car again.

I'm open to suggestions - do I need a new trans - or solenoids? If I need a trans replacement should I go new or used - should I go junk yard? - should I go Honda brand - or can I go with an Autozone Transmission ( 800-1500 for transmission - after they get my old trans back as a trade in )

Cost is an important factor ( I'd rather not replace the Trans if possible ) - but I don't want to get my car fixed up - with parts that will cause problems down the road.

Edit: I'm also on my Original Timing belt - so another expense in forseeable future.

Thanks