For kite buggying, I'd recommend quad-line bridled foil on handles.

Peter Lynn Kites make some good ones, as well as Ozone.

2m kite will get you going in over 20 knots
3m kite in 10 to 20 knots
5m kite in 5 to 10 knots

ozone octane or ignition with the bar option, no reason you carnt use a standard lei kite to keep the cost down, after the buggy grab a landboard then progress to the water youll be ripping in no time, one of the smoothest kiters ive seen on the water is chasta a snowkiter, check out flyozone .com for other options also ebay uk usually have plenty of land kites as it has a pretty big following there.

yes a 2m and bigger kite will definatly get you moving in a buggy
but will be useless for landboarding or kitesurfing

just for the buggying side there are so many options and heaps of older kites that make great buggy engines
but if you are just starting out and don't want to get P!ssed off and quit early on then you definitely need to get yourself a four line foil on handles this is so you can keep relaunching it without getting out of your buggy (in most cases anyway)

there are so many four line foils it is difficult to narrow down the options
but do stay away from any very high aspect ratio race kites these are for experts only - and even then not many buggy pilots use them unless they are speed freaks or they use them to race - they are harder to fly than just about any other kite

one reccomendation i will make is the ozone samurai (not the samurai 2). .
if you can find one it will be very cheap as they are years old and are perfect for what you are looking for great safe power machines that seasoned kiters still love today

later if you decide the sport is for you then you can use literally any kite at all and take em out on the water to (closed cell foils or inflatables for kitesurfing)

buggying won't help you with all aspects learning to kitesurf but if you nail your kite controll you'll be way ahead of the standard beginner

Hi again,

just remembered a friend of mine has a 4m Gin Zig for sale
Low aspect, great kite to learn to fly and learn to buggy with

He's looking for $250 (ready to fly)

Cheers