Strong example why many men should not shop at Suit Supply. It is mostly for slim men, and it does not carry the full range of sizes.Try, for example, Brooks Brothers in a size 43. 44 is also a possibility. 42 would be too tight.
"I think I am size 42R or 44R" isn't specific enough. Waist size, etc. are needed. Otherwise, go to at least a Brooks Brothers for measurement before doing anything. Dark blue and dark gray are the only reliable color options.