publications - Acknowledging the discussion with someone in the paper but excluding this person as a reviewer: how to do this?

While writing a paper I discussed its first draft with a certain colleague (he is from a different university, so it is not likely that he will be automatically ruled out as a reviewer as suggested in the Visoft's answer). He made a few helpful suggestions but by and large didn't like the paper: he would like the results to be compared with the ones one could obtain using his favorite method -- but this is a separate piece of hard work, and his favorite method is, to put it mildly, far from being universally recognized by the community of experts in the field.

I would like to acknowledge his helpful suggestions in the paper but at the same time I would like to rule him out as a possible reviewer (some journals give you an opportunity to let them know whom the paper should NOT be sent for review).

QUESTION: How should one word the acknowledgment of this colleague's helpful suggestions in the paper in a way compatible with excluding him as a possible reviewer, so that the editor who will handle the paper does not get confused by the whole situation and honors my request to exclude this person from the list of possible reviewers?

Also, which is the best way to state the reason for excluding this person from the list of reviewers (conflict of interests, or something else)?

Thanks in advance.