I spent the day doing "drag the bitmaps from project to project" type recolors, so I can assure you that if you follow Warlokk's tutorial, you should be able to easily resize clothing to fit your Sims.
You'd have to have the other size meshes in your Downloads while doing the resize, but you can remove them (and the "donor" clothing, as I call it) at the end so you don't have them in your game.