You could check with AMR in Leduc. What type of service? Amine? glycol? I might be able to get you some sizes and volumes, but as far as the construction end goes I won't be any help.
http://www.amrprocess.com/natural-gas/gas-dehydration
I've seen a few shell/tube exchangers from Alberta Exchanger too. You could try them as well.
http://www.albertaexchanger.com/contact.html