Hey CuzzA,
Couple of things.
1) Test it out but a 32 should do. Eric has much the same gear as you except a HP 120 plus steel backplate and his 32 hog wing is more then adquate
2) Consider more line on your reel. Don't know how deep you plan to go but I prefer at least 1 1/2 to twice the line as depth and consider a backup reel/spool in case the first is lost
3) Spare mask. It is part of the solo package but I too choose not to carry one, I don't use pockets. If you choose not to carry one, have a alternate lost mask plan. Mine? Keep my wt slightly negative and reel in the line at a speed that I know from experience will give me a safe ascent then have a knot in line at 20, 15 and 10 feet. I know others that place knots at regular intervals, such as every 10 feet
4) I also choose not to carry a snorkel
---------- Post added December 27th, 2015 at 12:11 PM ----------
As for solo class, that will depend on you. We chose to take the SDI solo. I thought I had an outline for the class but can't find it. As I recall the focus of my class
Gear and how to use it
Navigation
Shooting DSMB
Removing gear at depth and trouble shooting gear issues as a solo diver
But more then any skills education, it is the emphasis on the mindset that may be most useful to the select diver, others may come to the course with that already in place.
Get the SDI solo book. Look it over. Talk to the potential instructor. Then decide. I would say that taking the course is worthwhile for any diver that is just starting to dive/solo dive. Or of course a good mentor.
Edit: And just noticed your dive count. I am sure you already know this but 100 dive count is a requirement for SDI solo.