Easy way to determine how much Travel Trailer I can buy?

Thanks all,
Our Current TT is 2007 Rockwood 8293SS -
GVWR is 7643; UVW = 6146 lb- No problems towing this TT

Tow Vehicle - 2010 Chevy Silverado 1500 4x4 6.2L Engine and 3.42 axle with Tow pkg. GVWR 7000lb GAWR Frt 3950LB, GAWR RR 3950LB (also have Wt D Hitch & Equalizer Anti sway)May have to look around for any other numbers on truck

We also decided this evening that we will only look at new TT's under 7000lbs just to be safe.