I tow with the same Sequoia you do, except a 2010. For a "couples" TT, you have a ton of options out there. You could play it safe and shop by Gross Trailer weight and stay under 7,000lbs and still find plenty of options. Or look for dry/unloaded weights between 5-6klbs and also be plenty "safe".
FYI, its not weight to be concerned about. Our 5.7 is a BEAST. Its the overall size you want to be cautious of. (Length and even width is something to consider if you are shopping)
You have a fantastic SUV for towing, unless you're towing all year round and nationally. Then and only then, would I say look for something larger and more powerful.
