a few Halloween stores are starting to carry FX lenses if you don't need a prescription.
some brands to look into are wild eyes and crazy eyes,
(VampFangs carries one of those brands i believe...)
one thing to think about with cat lenses and other lenses that have a specific design is that only some contact companies have weighted lenses, but you may have to ask about it when ordering them.
this means that that lens is heavier on one edge to keep it from spinning and rotating every time you blink.
they may cost a bit more but they are worth it if you want a consistent appearance.
and yeah they do feel a bit awkward and might create a colored edge on you vision but after 5-10 mins you stop noticing it