Yes, the Jetronics valve plugs directly into your receiver. I prefer a slider switch for mine.

I don't think you will have a problem with weight considering you are using the Wren 54 SS although it is better to stay lighter if possible. I have seen this plane on the 12# thrust engines perform very well. I have the Simjet 1200 SP in mine which produces about the same thrust as your Wren and it's a rocket.

how much fuel capacity will you have?

Brandon