I don't think it will work with other brands. more so the software won't support it, then the plug will be different.
why don't you wan to stick with humminbird
if your looking at getting a colour sounder the cheapest was is to probably stick with Humminbird, that way you should still be able to use your current GPS receiver.
If you change brands you will have to start from scratch again.
either way. your looking at about $1000+ if you buy in australia.. or AU$800+ if you import from the US.