Im pretty sure you can only use auto trans with column shift ,do not think they make a 3 on the tree column. with a floor shift column you could go auto or standard.
Id recommend reading threw a few builds that use straight axles ,here are a fewthat converted to power steering
http://www.67-72chevytrucks.com/vboa...d.php?t=549739
http://67-72chevytrucks.com/vboard/s...d.php?t=471975
and one using stock gear box
http://67-72chevytrucks.com/vboard/s...d.php?t=562795
converting to power steering can get pricey, I don't know what your fabrication level is and budget,
FYI: if it were me Id use stock column and gear box( that will work with your drop axle )
you can add on a blinker switch for around $25, external horn button for $6 , just add a steering wheel. focus on drive train 1st, then after you get it running and stopping address whether to convert to power steering.