OK a LEI kite for J.
There are plenty on the maket that fit your need. I think for a good alround kite go for a 12-14m sq kite thats actual area not projected. Now for the type of kite. Dont go for a high aspect ratio advanced kite please, it will ruin your fun and you really only should get one after 2-3 years kitesurfing. I have naish X2s, great kites but my 12m can really kick my ass when trying new moves when jumping. Its not a fun kite for a beginer, especially the smaller kites (12m and below). A guy who was just starting bought one recently and can hardly do anything with it, he stuggles then get his ass kicked, not wise.
Naish is good make and last years Aero 2 kites seem to be going cheap, might be a good idea to get one of those. The aero is an intermediate kite so you wont grow out of it quick. Actually that statment is not really true cause alot of experts will use it in gusty winds instead of the X2. They are top kites slightly lower aspect ratio than the X2 makes them more stable, better in gusty conditions and far more usable but also able to get good high and floaty air.