Mirage has been promising some 4-pipe destroyers (1:400 scale) for about three years now. They have finaly made it onto their website with a release date of sometime this fall. Included will be the HMS Campbeltown plus one other Lend-Lease ship (the name escapes me right now).
WSW/DocModell makes a very nice resin 1:700 scale Lend-Lease 4-piper as HMS Burwell. It takes some time and care to sand the fine guns out of their wafer carriers but the model makes into a nice little ship. Like all WSW/DocModel ship kits there is no PE included.
White Ensign has a 1:350 scale resin & brass Lend-Lease 4-piper in the works. It keeps getting pushed back in the queue. It will be HMS Montgomery. (I'm waiting for it to make HMS Mansfield -- as in Mansfield, TX -- for which I have photos from the Imperial War Museum.) White Ensign makes the USS Reuben James -- a 4-piper which has US weapons.
Commanders/Iron Shipwright makes a 1:350 scale resin & brass US 4-piper which can be made into one of 4 configurations. It could be made into a Lend-lease version with some scratchbuilt RN weapons. It is sold as the USS Decatur. ISW also makes a 1:350 scale resin & brass HMS Campbeltown in StNazaire configuration.
Classic Warships made a 1:700 scale resin & brass US 4-piper as the USS Ward. It too could be made int a Lend Lease ship with some replacement weapons. I believe that Trident Hobbies has picked up the production rights to that kit. While on the subject of the Ward, Gulfstream/Commanders/Classic Warships produced a 1:350 scale resin & brass Ward. It was the same kit sold under each label.
Revell made a box-scale (1:240-ish) styrene 4-piper which has been sold as the Ward and Campbeltown. It did not represent the Campbeltown at StNazaire. It can be made into a very nice kit with some work (sand the wooden planks from the steel decks) and the application of the Gold Medal Models photoetch set.
Combat Models makes a vacu-formed 4-pipe hull. It is NOT for the faitn of heart. You must have a high tolerance of pain, a large supply of Evergreen, a good stock of patience , and excellent scratchbuilding skills to attempt the kit..