The Panasonic LX3 and Canon S90 both have wide angle lens. And, being a compact, you'll not get dust on the sensor (something that will happen to a DSLR over time (time dependant on variables such as how often you take the lens off etc)). The LX3 and S90 both have fast lenses too, however, for photographing kitchens you'll likely want maximum depth of field so you'll not benefit from these wide apertures. However, for square on shots you could find them useful for quick, handheld, shots. (Basically, you've got flexability). For max depth of field, use a tripod.
Quite often, for on-site shots, you'll find the light is coming from one end of the room (galley kitchens, for example). You'll want a remote flash or reflector or something similar to boost the light levels across the whole scene and reduce shadows. I'd go for the aforementioned Nissin in slave mode. The power is adjustable and it's triggered from the camera flash.
The reason you might want to emply a pro is because he (should...) have sufficient kit to handle all the variables that will present themselves on-site. In a studio you have a lot more control so perhaps less need to employ a pro if you can capitalise (and control to some extent) the available assets (e.g. natural light).