i think you might want to look into NXT.... they have everything you need and its quite under the radar at the moment with active development. they just have a problem marketing themselves...

If your a bitcoin purist, then ignore my posts. Because if bitcoin was to do anything close to what nxt has right now give it at least 10+ years seeing all the rage over 20mb blocks.

Don't get me wrong, I'm all for Bitcoin too, but it just doesn't work in certain applications. I see NXT as a platform not a competing currency... its a shitcoin honestly, but the platform is something I've never seen that any coin has even come close yet, even ethereum.

Put the Bitcoin purist mentality aside for 10 minutes, and just check out what these guys have done. i was a bitcoin purist myself.. http://jnxt.org/nxt/