Start from the end I guess.
Every 1G-GTE I have seen has a A/C compressor bolted onto the engine. I have a spare a/c comp from a 1G-GTE if you can't source one over there.
Steering problems won't relate to the auto box, more likely trying to make the Corona struts fit, which are longer than the original TA22 units. I would look there first.
I have corona struts-vented disks and rear drums on my RA23. It works more than fine. Pedal travels further with the original master cylinder having to move a greater volume of brake fluid for the larger calipers. If this is a concern for you, upgrade to a T18 or RA40 master cylinder, both of which are larger (13/16ths) than your TA22 unit (at 11/16ths).
Tip for new guys: Use the SEARCH function and sit back and READ. This forum contains tonnes of information.
Good luck with it all.
Mitch.