With the board bag, go the 10 mm over the 5 mm. Nothing wrong with the 5 mm, but for my 12' I think the 10 mm was only about $30 more (or thereabouts), and worth every cent. Also consider the zipper length. Again, not much extra for longer zippers, if thats the way you want to go.
One thing I've noticed about the two Munoz's I own - may not be specific to gliders, per se, but certainly to the Munoz's in my experience. They'll catch anything. Especially, my 12'. Hell, I could fart in the water and ride the bubble. Nonetheless, they need some speed to boogie, like Beerdead said. No grunt, no fun. Based off my GPS watch, if I'm only going 10-12 kph on a slow roller, they're dogs. Once I get up past say 17 kph (overly specific, I know), that's when they really open up and start to boogie.
I've often wondered if that's where gliders sometimes get a bad wrap? If the waves are so crap that your only option is a glider, then it might not perform as you hope? (Again, like Beerdead said).
But for what you're chasing, larger fuller waves and knee to head high runners (particularly waist to head high), I reckon you'll have an absolute blast.
And as noted, getting them to and from the water can be a workout on their own. Somewhere like Currumbin, I'll opt for the short walk and long paddle over long walk and short paddle, but damn can they paddle. Speaking of Currumbin, I've had some awesome sessions on the 12' sitting wide towards Lacey's with the SUPs. I can sit further out, and be on my feet before the SUPs even get a decent paddle in. There's something intrinsically rewarding about turning the tables on the SUPs and getting the wave before them!
I've got a reasonably excessive quiver of boards: 9', 9'2', 9'6", 9'8", 2x 10', 10'1, 10'3", 11' and 12', and like I said earlier in the thread, if I could only keep one, it'd be my 12' even though I don't surf it much anymore. "If your 12' is your favourite, why don't you surf it more?" I hear you ask.... It's so fun and easy to surf, that if I spend too long surfing it, stepping back down to one of my go-to 10ish footers feels like a challenge.
I'm looking forward to reading the report of your first surf once you get your hands on it.
Cheers!