hiya...
I adopted the same strategy as you about a year and a half ago, tried my first half-assed water starts today...
I've taken the learning curve slow, but I've been in no hurry, flying on static on a good beach has been my thing for the past while.
look for scoopy's guide in the how to section of this forum, also have look at all the longer "newbie kiter -- what size?" threads from the past
month or so, those will answer a few of your questions.
the whole depower thing is not something I've tried yet, but I've spent enough time fiddling with adjustable angle of attack on a couple of my kites,
they need more wind than a fixed bridle to show their full depower range, and in general have a bit less power per square meter even when powered up.
If you're in a hurry to get on the water, depower trainer on land might be the way to go, but reputable lessons would be best.
depower with ATB: What I've heard is that the montana 5m would be good, but only in higher winds, say 12-25 for you, with full depower only kicking in
above 15-18 mph or so. Also the newer montanas are much better than the older ones, there are four sucessive models.
3m fixed is perhaps a touch more grunty than a 5m depower, depends on the quality of the depower kite's set-up.
guys with direct depower knowledge will have to fill you in from there...
btw, the 10m too small for 20 mph does sound a bit off, but it could easily be right, I understand, for a not-so-good inflatable kite on water, which
takes a lot of power...
cheers, keep doing your research, the answers are out there...
fixed bridles, flying static, been two years now... ??? folks must be wondering....
sting 1.7, dp power 2.5, crossfire 3.2, ace 5, blade iv 6.5, ace 8, ace 12...
also a couple of arcs, 12 syn and 12 phanny, but i\'m not yet up to speed on them.
(13.11.09)