You'll find from experience that the tipping point doesn't really exist. On a front engine car like the TSX or Z4 or a Camry for that matter the jack can be located under the front floor mats and the car will be perfectly stable. Then position the stands. Wear heavy gloves because those telescoping stands can really do a number on the hands.
Jacking with 1 jack takes much more effort because those 6 ton jacks are about 14 inches min. So jacking up the car 14 or so inches on one side is a little unnerving at first. Ideally, with 2 jacks you just lift the car up evenly. Perhaps 8 inches on each side and then another 6, then place jack stand on all for "corners" and then continue from there. Quickly you get the feel for it. I use that 6x6 to lift on the jack. Spreads the load out and extends the vertical reach of the jack.
Like anything this is a matter of cost vs. need. It's very tempting to go for those small stands (2 ton) exclusively (some are really poorly constructed (stamped steal)) because one thinks they'll seldom use them. However, once those 2 ton stands are extended, they IMO, aren't worth the absolutely catastrophic result if they either fail out right or tip over (vehicle siding off).
Watch for 1/2 price sales at Princess Auto.