The weak spot for arcs is sub 10mph. If your wind is often 10 or less then you may want to go foil. I can get a ride on land out of my 15m Charger and Syn as soon as mother nature can fill them. About 8mph minimum. They start to act as they should closer to 15mph.

I agree with kitedelight about the 12m Pulse II . A 13m + 7m Pulse is also a nice combo?

The thing about ARCs and pricing, is (generally) a year or two after they are out of production, the second hand price of them drops to like half of the original retail value. You could expect to pay about 400 USD for a 15m Synergy that's in great condition; used well, but no repairs. ARCs are a kite class themselves, but there are classes of ARCs within ARCs that affect their wind range. I.E. not all 12m ARCs have the same wind range. The higher AR (aspect ratio) ARCs like the Phantom and Scorpion require more wind to fly, but the top end is HUGE as well as an insane amount of depower... and if boosting big is your thing, a Phanny or Scorpion will take you to the moon. The lower AR ARCs have a much better low end, a bit less depower, but generally can be whipped around faster (especially the newer ones) for more grunt and lift. A 19m Synergy or Charger can probably get you moving at about 8 mph.

Since you live in the UK and have such a nice constant breeze that I'd kill for, I think it's unfair to rule out the possibility of an LEI. LEIs LOVE that island wind. Although they're best suited to water, you can have a blast with one on land. Bow kites are more efficient than ARCs, and they pull harder and lift higher for their size. Not to mention, kites like the Best Nemesis and Slingshot Rev are kiteloop monsters. You can fling them around like it's nobody's business. The reason land guys don't really like them is because when you live on a huge earth scab like North America, the wind is very gusty and LEIs don't perform as well in that kind of wind. There is also an increased risk of popping a bladder on impact. Another thing is, the valves will start to go after a few years. So they require a bit more maintenance. However, the depower and pop that these kites have is unparalleled, and you can get a 2008 Best Waroo complete (outstanding kite on all accounts) for 400 USD or less.

Just something to think about.

Arrives later to the thread....

I'll state it outright, I'm biased with my own kites. Ozone makes an amazing kite. They are nearly indestructible and very lifty and floaty (though not as much float as an arc). However, it needs to be mentioned that the manta has changed a lot over the years. The Manta 1 was very floaty, while the manta 2 had much more lift. Sadly I have yet to fly the M3. As far as the frenzy goes, it's a bit less performance for a little more stability, but by what you're saying, I'd go with the Manta. Also, as sean mentioned, LEI's are great in non-gusty conditions. I picked up my ion2 for $250. If you want to talk lift, then that's your kite.... there's my 2 cents