The ties and other bits should have style names and numbers and Jim's site. I'd just list them on the form. I know it's spendy to call from the UK, but that might be better done on a phone call. Maybe they could even look online while you guys chat about what pieces you want.
Ok, this is a wierd pic, but at least you can see Joe's tux. I'm just daring him to smear cake on my face! (thank goodness he didn't) The tux was rented from after hours.
You can see DHs tux pretty good here. All the boys wore striped black suits with blue ties, DH wore a white vest while the GM wore silver vests. We rented them from After Hours