To be able to sponsor a student visa you need to become a licensed education provider, and though as I guess some 'bogus' colleges have got licenses it would be possible to get a license it seems a lot of effort to go through. Especially as if they did perform any sort of inspection (which they are likely to if you only sponsored one student...) you'd fail it.
If you can genuinely get a company up and running that can have enough turnover in the first month or so to pay yourself a salary, then that sounds a good plan.
If though you are planning to start a company just to move your own money in and out of to pretend you have a income then I would think very carefully before going down that path. In my mind that is trying to obtain a visa through deception, which if caught could result in a long ban for your wife.