Gotcha. Well, I'm sure DC's should help you out then. A couple other things that come to mind. Make sure your textures aren't too large. The wood textures for the cabinets, for example. As of SU 6 the max you could display was 1024x1024. SU 7 has some sort of high res option in preferences which I'm guessing ups that, though. Anyway, SU will save a copy of the image you use as a texture. So the worst thing you could do is use a 4000x4000 pixel image as a wood texture because you won't see it to the full resolution for one thing, and for another SU will save that whole huge file.
Specifics for components...
Components could actually help you out quite a bit unless you get into custom stuff a lot w/ your kitchen cabinets. I use to do kitchen design at Menards (like Lowes or Home Depot but only in the Midwest). We had a program where you'd basically pull off specific cabinets and place them in. That could easily be done in SU by just making a library of your standard base and wall cabinet sizes, then just pull them off of your components pull down.
I'm getting all sorts of DC ideas too, although I haven't gotten into DC creation yet. You could almost just have a half dozen DC's (base cabinet, wall, drawer base, sink base, tall utility, etc.) that you could stretch and snap to your typical sizes (12, 15, 18, 21, 24...). And then you could use the interact tool to cycle between different knob and door styles and even finishes. Heck you could even use it to toggle the doors open and closed!
Lots of possibilities, but now I've gotten way past file size. Basically the benefit would be that all of your doors (of like size) would be the same component, your hinges would be the same component, knobs, drawers, etc.
-Brodie