Will you put 406mm or 451mm wheels on the bike?
If you want a chunkier tyre than what's on your road bike, maybe 406mm (standard BMX sized) wheels would be more ideal? I prefer this size myself because in an emergency it's easier to source spare tyres and tubes. Also, because 451 wheels generally take skinny racing tyres, the smaller 406mm rims generally make up for the size difference when you put on a chunkier tyre because of the difference in tyre heights.
Kenda Kwest tyres are cheap and roll well. Right now I have Swalbe Marathons on my bike. I don't think that these are particularly inspiring fast tyres, but they are very well constructed and I estimate that I've done several thousand Kms since mounting them and haven't had a puncture. There's something to be said for that while on the road in foreign lands.
Also, my personal preference would be for a titanium frame over carbon fiber. More durable and more beautiful imo. I might be wary buying something like that unseen over the internet though.
Anyway, good luck, and please post pics of the build when it comes together.