I bought Carlisle Radials. Key is I bought the highest load rating tire I could in my size which was "D" only needed "C" about $6 more per tire for "D". Pulled boat to FLA at 75 mph, when I checked tires they were cold. I have to believe if tires stay cold they aint going to pop, lol. Only mistake I made was balanced them on old plane balancer. worked good up to 70mph then had one hop. get them dynamically balanced if pulling on interstate.
You have big tires for 5K load, 15" surprised not 14". You should be barely loading a 15" tire should last forever.