Hi Mick,
Welcome to your new addiction, and to the world in which your ability to discriminate hype from truth will be at a premium. I'll offer my 2c.
Build quality doesn't get any better than Ozone. They're a paraglider company too so they know a lot about precision design and manufacture and quality materials.
The Catalyst is elegance on 4 lines - not sure why you'd look further for a perfect kite for beginning and progressing.
Obviously rebels work - I don't want to diss them gratuitously - but seriously, what's going on with your design when you need battens in addition to 5 struts to keep your kite stable? And the rear line bungees? Seems like a lot of inelegant gizmos to me.
As for 5th line vs flagging to a single front line - each side has its adherents. Personally I prefer the simplicity of 4 lines and the reassurance that I wont wrap my kite if it rolls through its lines.
There are some recent threads such as this one -
www.seabreeze.com.au/forums/Kitesurfing/Review/Ozone-C4-2012-North-Vegas-2012-OR/ - in which various (experienced) riders have reported their extreme frustration with the North depower rope replacement fiasco.
I've used a lot of kites over the years and the 2013 Catalyst is the most elegantly simple, versatile and fun kite yet. Have a close look at all the kites on your list, check out the stitching, the panel layouts, the reinforcing, the grading of materials for strength/weight and let me know if anything comes close to Ozone.
Then fly them, and I have confidence your decision will become clear.