I suggest you buy a steel framed road bike. There isn't a huge selection but there are enough around to be able to find one without too much trouble.

Cyclocross bikes have just about NOTHING going for them for the sort of use you're contemplating. Newer designs have funny geometry that are ideas of the different designers. In particular cases each one of these geometries have their purpose - for instance - high bottom bracket CX bikes such as Redline work very well in deep mud, low BB bikes work better in ice with their lower CG. But as a road bike used almost exclusively in good weather you are limited by the quirks of a CX design.

This isn't to say that ALL CX bikes are quirky but enough are that it's a crap shoot on your part.

You are big and heavy but you aren't rediculously big and heavy. I just rode today with a guy that's 6'
8" and 245 lbs that rides a 68 cm bike. He FOUND a custom bike in his size! You'd probably be fine with a steel framed 64 cm road bike.

I'm 6'4" and around 200 lbs and ride a 61 or 62 cm bike without a problem. I've found MOST of my large stable on the internet so you can too.