I've got the $15 spools from Dive Sports also and they are very good quality. Delrin mold and good line. (can't remember exactly what kind of line).
One thing to check on your finger spools when buying is to ask about the line and see if it's braided cave line, wreck line, or just cheap nylon line. The braided line is much stronger. You'll typically get #24 or #32 (I think) line on spools and reels if it's braided. The only difference is strenght and thickness, which of course also related to how much line you can put on the spool/reel.
No sense spending more money on a spool that has a fancy namebrand if there is a no-name with the same quality.
I'd get the spools with the day-glow yellow line if possible as you can see those much easier in the water. But since you're taking a DIR class, not sure if yellow line is considered "DIR".
As for SMB's, there are huge differences in mostly design. Everyone makes them slighly differently and in different lengths/widths and with different features.
Things I'd say to use for consideration on a checklist for your SMB.
- determine the length/width you need.
- Get one with a inflator diaphram for inflating at depth with an octo. (Smaller ones come only with an oral inflator).
- get one with a dump/overpressure valve. (two reasons, one for dumping air if you're staying with it or using as a small lift bag, or second so it won't burst if overfilled as it ascends towards the surface. Note if the dump valve is at the bottom of the bag, it's pretty useless for using as a lift device or dumping air anywhere but on the surface.)
- Some SMB's come with a "self sealing" diaphram that won't let air out at all.
- Some SMB's are dual color (yellow on one side and orange on the other).
- reflective SOLAS tape is always nice.
- a d-ring at top to attach a strobe to is good. (D-ring is also good for wrapping SMB around you and clipping it off as a life ring if needed.)
- some SMB's have a plastic holder at top for a light stick.
- I like the fact mine has a brass snapbolt (single ended) for snapping to my BC bungee to double secure it and also use that snapbolt for attaching to loop on my finger spool line.
If anyone else has suggestions of what to consider, please add them.
After you get one, go to your local pool or quarry and learn to shoot it from your safety stop and from depth. trying to learn this in a stiff current on a boat dive could just result in a line going everywhere and having to deal with it in open water. best to play first in confined water.