I'm imagining this sort of statement:

He's a... different... sort of person, I suppose.

Some people would pronounce 'different' in that sentence as though it was followed by a question mark, but not the rest of the sentence. However, writing it like this strikes me as wrong:

He's a... different? Sort of person, I suppose.

The second sentence doesn't look grammatically correct to me. That being the case, how would I indicate the change in tone accurately in writing?