General wisdom is that you use studio strobes if you need more power/light. You use speedlights if you want portability and your lighting needs are modest.

Most of us start with speedlights because of the Strobist website. It's where a lot of us learned to light. And the reason speedlights are central to this style of lighting is because most folks already had one, and they're very small, portable (battery-powered), and cheap. And unlike a studio strobe, you can use one both on and off the camera. So that same light you're setting up for a studio product shoot can also be used on the camera for a run'n'gun event or social shoot, and are easier to take on location.

In addition, if you're shooting small still lives, with relatively small subjects, then you can actually work in much closer, and you'll need less light. So, speedlights are probably going to be more than sufficient for what you want to do in your other post. The question is what else are you going to need the flashes for?

It's when you need to shoot, say, a family of five, outdoors in bright sunlight, that a speedlight might not cut it, power-wise.

OTOH, getting two $70 manual speedlight and finding out they're not powerful enough at the highest setting is not nearly as much of a mistake as getting two $300 studio strobes and finding out they're too powerful on the lowest setting. :)