Recently finished construction, painting my 20'x24' shop. Raftered
roof, 5/12 pitch, 8' walls. The roof has gable and soffit vents. It
also has it's own 100 amp service. T-111 siding with foamboard on the
center sections and OSB on the corners.

My question is regarding insulation and wall covering. I have not
insulated yet (1 bill at a time!) and was thinking about doing R19 in
between the joists and R11 in the walls. (I'm in the mid-south - think
Memphis). I feel like this would be adequate in the winter months,
but will it do anything for me in the hot, humid summers (I'll buy a
window A/C next year.) Should I have anything directly under the roof
decking & rafters?

Also, are the any options to drywall for a ceiling and walls? I loved
Matthew Teagues idea of using the T-111 on the _in_side for a wall
covering, namely it's strength, and I really hate sheetrock, but the
T-111 would be expensive. Ideas?

Finally, would it make much difference to just lay drywall on top of
the joists and then the insulation on top of that? (I'm thinking I'd
like to use the joists for hanging things, and gain that extra 5.5" of
space.

Thanks for any ideas!
Duke