1st, having spent nearly a lifetime as an RCer and lakefront resident, I would suggest getting to know the new plane a little on land prior to installing the floats - unless you'll be making those first few flights off ice/snow.

2nd, not sure how much engine experience you have, but in dealing with Hobbyking I would warn of the very little support you'll have available to you there, assuming you'll be able to get any at all. There is no hot line available for those having troubles, that's just about guaranteed. If you weigh this lack of support with what you save on your purchase from them, MANY claim they would have been way further ahead dealing elsewhere. That said, if you're one of the few able to do all your own work and willing to take the risk, there are good deals to be had on occasion. Suggest you make all purchases via credit card to allow you some assurance you'll have final say on your purchase.