Depends on local condition and wind, If you plan on learning on 9m, definitely get a C kite with fifth line, like Torch, GP. I guess Vegas, Fuel (if not gusty), Chaos. C4 seems to get good review too. haven't tried RPM and others.
Wind for 9m and speed of kite make it quite essential for kite to catch you very early (unless you boost of a ramp than sends you 30 feet up...).
If it is a smaller size like 8m or 7m you can probably get away with learning on any other kite. Also C kite are a lot cheaper used
since it has a "pro" reputation.
I tried Ocean Rodeo Razor 10m, it loops well but quite grunty, not sure how 9m is but from what I have tried I don't recommend to learn on... Also I don't really like how the power builds up in that kite, hard to explain. Maybe 9m is better.
Anyway I tried learning on Bandit 9m with stock line, it was quite a pain, by the time I got a C kite I could land some when condition where perfect but as soon as I switched I could land 99% of time even on poor looping condition just because kite catch you so much easier.
For example Cabrinha FX 9m is supposed to be great looping kite, I can loop it but I can tell back to back the GP catch me a lot earlier as soon as I sheet in, when FX you need to initiate the heliloop a bit earlier.
Another thing is that some hybrid kite have a weird power in the loop, the kite doesn't pull right away but when it accelerates it yanks you on a weird spike, which is hard to handle when you learn. on C the power seems more constant even though perhaps a bit gruntier.
Once your technique is better you can loop anything but in the beginning for a 9m I think you need a C!