A 46 in the trousers should fit you perfectly. From what I've seen (and own), the more recent 48s measure out to about a 34" waist.
Trousers will be tagged a 46. His denim is where you'll see 31 on the tags. I haven't tried any of the jeans on myself, but the actual measurements look like they fit TTS to 1" big depending on the style.