I would suggest you get a bigger one.. Remember the volume should be the amount your ingredients when you start off with.. with the cooking, final skimming etc.. you won't have a lot left... especially if you want to save money and time to have several meals in one go.
Also for considering $ and environment; I prefer the ones with simplest knobs. If I want the cooker to be timed, I use one of those old school mechanical timer plugs. I avoid anything with soft touch PCBs, they last only for a few years, then the controller breaks. It took me forever to find a dishwasher that has a stainless steel tub and a mechanical timer