Jack stands are rated as a pair, so you should be fine with 3 tons(6,000 lbs).
A two ton jack would be enough, since two tons is 4000 lbs and you probably won't be lifting more than 60% or so of that 3600(2160 lbs). All that said, if you are interested in a frequent-use jack or more safety, I'm a fan of large-footprint-and-saddle jacks, preferably aluminum, not the typical 2 ton jack with a 2" diameter saddle.
Here's the one I use for all my vehicles, some of which are 4500 lbs: smile.amazon.com/gp/product/B00132CGEW
There are plenty of similar competitors.
Stay away from the ones with tiny saddles, as they usually have tiny 'footprints' as well, are more likely to tip while jacking, and don't lift as high.
I got this one a while back, but I don't think it qualifies as 'not very expensive'. Note that when I got it, it was $199. https://smile.amazon.com/gp/product/B00132CGEW
Having it be made of aluminum was important to me, but if yours is always going to stay flat on the floor its probably not necessary.