I had the same issue but I stumbled upon some Nitto NT420V tires...got the 285-40-20 for the rear and 265-45-20 for the front and am happy with how they ride..
You could always step up to 315/35/20 and 275/40/20 combo. Those sizes are easily available. I'm ordering some Cosmo MuchoMacho's for my Jeep. Have them on my Hellcat and they perform great at a reasonable price.