1000 billionaires, sounds like a great plan. They did so well last time.

Getting the flotation is actually not that difficult in terms of engineering since Venus has a crazy thick atmosphere. Not hard to float a balloon at an altitude of a few Earth atmospheres. Problem is your life is dependent on the reliability of the floatation system. It would take a lot of attention to fail safe design. That OceanGate organization would be like "the wrong stuff".

There's other engineering challenges in colonizing Venus such as solar radiation. Venus has no magnetosphere to protect against ion radiation from the Sun and being closer it's much more intense than Mars. Then you'd have to tether the balloon somehow, Venus has some strong vertical winds. That's going to be like thirty miles of cable to the scalding 900F surface. Venus has clouds of sulfuric acid so that's going to present a materials challenge. It's a tough sell, greatly easier to colonize Mars.

It's like when Elon started blowing smoke about colonizing the moons of Jupiter. If not already aware, Jupiter emits the most radiation of any solar body second only to the Sun. The moons around Jupiter are seriously toxic to human life. They can't even get a probe to last more than a year around Jupiter due to radiation exposure, let alone a manned spacecraft.