I currently ride a 12 dice In melbourne around the bay. Love the massive air you can get with the dice but I'm sure you can go bigger, I wanna try and get into the airstyle board off one footer tricks etc...

What's some sick kites with massive boost and hang time?

Dunno about north kites unless the 2015 bars are better than the 2014.

I'm leaning towards air rush but know nothin about them never ridden one?

What are some options?

^^^^^^^^^^^^^^lol, that would be the Squirter!

where were we? Oh yeh
Bandits, Vegas and Screamer's

Biggest jumpmachines in my area are Edge and Screamer. There was some skinny old man on Switchblade getting really high but he has 15 years of experience. Thats my visual experience :D

Tall order really.
Explosive boost = high aspect
Huge hangtime = low aspect
(as a general rule)
But there are a few odd balls out there that deliver a workable duo.
One of the best (imo) is the Best Kahoona - certainly yanks you skywards and flown with skill can offer loads of hangtime.
Lots of others similar Im guessing.
Look for a mid aspect delta style or mid to low aspect hybrid - they are the only designs that will deliver on both counts.
SS RPM is another one that springs to mind.

One or the other is easy to find - getting both from one kite requires selection and skill.