Futaba makes pretty good radios. Give thought to a 2.4 mhz system, they avoid the issue of dealing with crystals. A radio such as the Futaba 3PM would be a good upgrade. For servos, the first consideration is choosing ones that fit in the existing spaces. The MM isn't too big, so you don't need to spend extra on heavy duty servos. And finally, not sure if you're aware of this or not, but there's a club that races across the bridge from you over in Queenstown. Looks like it's about a 45 minute drive from where you are. They don't have a web site yet. PM me if you want contact info.