If you want to go any lower than the "normal" low, you'll end up with not enough suspension travel, and/or uncaptive springs. To solve the suspension travel problem you'll need to get struts shortened, which would mean finding shocks that are also shorter and modify to fit. A lot of work just to make your car low (and probably illegal anyway). To solve uncaptive springs you'll need to get short stroke shocks, or get helper springs, which are expensive and you can only really get them in coilover sizes anyway.
In any case, I wouldn't bother going any lower than your "normal" low. It generally makes the handling worse, and it gets expensive rather quickly. If you want a car that looks low but isn't all that low, get a Datsun. To get a Corolla to look very low you have to basically sit it on the bumpstops.