leopard cactus (L114) are available (there's two at the Hutt Pet Centre) but they can be stroppy, grow reasonably large, and as with goldie plecos they are carnivorous.
There are a number of smaller species of Pleco that would be good options (several have already been mentioned): the smaller Panaques (clown plecos, Flash or Peru striped panaque, tiger pleco), Hypancistrus (chocolate zebras, king tigers), and the so-called 'big band tiger pleco' (a Peckoltia). While they are not quite as colourful as gold nuggets, they are all small species and easy to look after. If you've got a large tank I like royal plecos. They often come out to feed and look great but they do grow large. As for coming out often, based on my experience, if they are comfortable in their surroundings, which ususally means plenty of cover and lower lighting they will come out more. I agree with Jamosfish, its hard to predict what an individual pleco will be like. Avoid the stroppy or difficult ones, and go with what you like. Hopefully they'll come out. For value for money and good looks, chocolate zebras are pretty hard to beat.