I presume TA = travel agent? Are TSA (whatever that stands for) locks an American thing? I've never seen them for sale in Canada. Never yet had a problem traveling with "normal" Master locks but want to avoid potential issues too.
Those TuffPak cases appear to be extremely bulky (and expensive!!). I think throwing a whole bunch of detritus in with guns is just asking for trouble with airport/security agents ... or others waiting their turn for inspection. Wheeled luggage is something begging to get crippled. At the carousels I see way too many wheels broken off or dangling. I use trolleys and they handle my non-wheeled gun case and checked bag just fine (carryon pack and computer bag are strapped to me). If no trolley available, I can unzip the shoulder packstraps for my checked bag, put it on, shoulder the computer bag, and carry the gun case and day pack in each hand. Not fun but I can manage ... until I can find a trolley.