The new (2010/2011/2012) Carve 111 is a terrific little board for a big guy.
I have the 2011 model and like it alot.
It's very easy to sail and jibes like a dream.
As far as using it with a 4.5 m2 rig..... that would depend alot on how big the chop is in your 4.5 m2
If you want the extra "float" (I believe you mostly sail on fresh water in lakes and rivers, right?) of the 111
over say a 96-101 liter (better for huge voodoo chop) it can certainly work for you.
You might be able to uphaul and slog on the Carve 111 where a 96-101 liter board would be a definite "sinker".
I would suggest "expanding" your expectations for the Carve 111 to cover 4.5 m2 to 7.5 m2 + as the board has alot of range if you are willing to pump a bit to get it on plane in the lower wind end of it's
On the hgiher wind end of the range (4.5 m2) it's going to seem a little big, but you have the weight to hold it on the water, and going any smaller takes away the uphaul and log possibilites on fresh water.
Hope this helps,