Far be it from me to suggest anyone to stay with VocoPro, but I do have to ask -- how does it sound compared to your local karaoke host? If you are not totally disappointed with the sound, I would stay with it a while until you figure out precisely where you want to go.
If you really want to gig out on a regular basis, I recommend you look at portability and ease of loading as a high priority. I now can fit into one rack, with laptop, mixer, light speakers, and a couple of gig bags with stands and mics. I don't do a lot of gigs, but I want to keep setup down to a minimum. That isn't the fun part.