Stoked to see that you are getting into the game Zokeimo!
For a guy your size and weight we also need to know average wind speeds. I think Georgian Bay can get quite windy so we will assume you will be kiting in 15-25 knots. In this case, I would say you would be best to get an 8 and a 12m kite. 12m 1st, 8m second.
As for 2nd hand gear, that is your own call. For sure you will be rough on your equipment the 1st season as you will be unfamiliar with it and learning but the newer the equipment the better designed and easier it is to fly. For example, I feel our new 2011 Razor kite is the best beginner kite we have made even though it is actually a high end freestyle / wave kite. It is very stable and easy to re-launch and can easily be de-tuned to a beginner setting to allow for simple use and predictability.
However, if you do elect to go 2nd hand I would advise you not to buy anything older than 2 years old as equipment will degrade over time and has made significant improvements over that time and I would also advise that you bring a knowledgeable friend to the purchase to inspect the gear for wear and tear and over all condition.
John Z - OR