PTO brake for sm-465

[mud slut 350]

So i put a sm-465 in my K-10 and have a 14bff rear. It currently has drums but i will be getting rid of them soon for disc conversion. I need something for a parking brake. I was looking into line locks cause ill only be using it for short periods of time if on the trail or goin to the store or somethin then chok the tires if needed for seetin long times. right now i just leave it in gear as the parking brake is non functional just havnt hooked it up since the rear axle swap. Was wondering if there is such a thing as a pto brake that will lock the trans? I thought bout a driveline brake but they are $$$ and id rather look for a cheaper bolt on option where i wont have to mess with driveshaft lengths. Any info would be great!