If you do, you can do some test measurements to see what you will get from the combination of the film speed, the light output of these flashes and the reflectors or other light modifiers you will be using.
My guess is that you will find that an ISO 400 film will be more usable than 100 or 125 - 200 watt-seconds into basic reflectors means at best moderate amounts of light when normal portrait distances are involved.
For close-up and still life, they may provide more than enough power. To do a studio portrait of an extended family - most likely they will be stretched.
Strictly speaking, the watt-second measurement is merely a measurement of electrical power. Better flashes may make more efficient use of that power, and therefore produce more light from each watt-second of power, but these are probably at least usable.
You may find having just two moderate power flashes limits you a bit. Lighting backgrounds or hair works better if you have another light source available, although small portable flashes can be used in conjunction with these studio units to good effect.
These are probably good to learn with, so don't dismiss them out of hand. If you find yourself bitten by the studio lighting bug, you will soon find yourself wanting more .
One caution - be very careful about anything you see that recommends using a digital camera as a flash meter. The differences you will encounter between a good flash meter and a digital camera when it comes to measuring light are sufficient to make it inadvisable to use the digital camera for that purpose.