What Boat?

You could try the Vortex. Suitably depowered it would work OK with your weight.

But as others have said, you are probably better off starting a few rungs down the ladder. Even if we assume you are very talented (and not in the way that Stuberry means) you haven't enough experience to have sailed in all conditions, even in a Topaz. And in a singlehander you have to work it out all on your own.

Time on the water means working it all out when the conditions suddenly change on you or something on the boat breaks and you have to get it home. There really is no substitute for it. On the way you'll experience all the things that you learnt in your classes and start to put a perspective on things like balance and trim and apparent wind.

But if you are looking for a milestone to indicate that you could handle a Vortex (and there is a big jump between that and a 600 or 700/MPS) then if you can comfortably crack gybes in a Radial in a Force4/5 then you'll not cause too much damage when moving up.

having had a day to fall out of a 700 this weekend i would very definately not recomend jumping straight into a trapeze single hander. i have been sailing for years started in a cruiser then my parents got me and my sister a feva now have a standard rig laser and when i went out in a 700 this weekend i found it difficult. the heming from the wire bit is easy, its the getting onto the wire with all the sticks and bits of string and turning the corners that is the worst bit. you need a 2nd pair of hands.

as for the contender from what ive heard you need quite a few pies to keep one flat but thats just what ive heard.

i would say go for a laser radial/europe/byte for a few years to get used to the racing thing and the getting around a course and stuff then when you think your ready try something more challenging and by then you may also have found someone to crew for.