Try these guys
www.paspeedo.com

Been using their services since bent was a pup and the 911 series wasn't in
production.  Vast knowledge there.  Klaus is retired but his staff is
excellent.  Best to have all your ducks and cows in a row though as they are
quite busy.  It would be proper to purchase the sender from them as a
courtesy for their help.  They ship promptly and guarantee their products.

Al