I am planning to add a left hand turnout to my layout I am building.
I currently have four electic point sets on one control box.
It would make things easier if a curved lh manual turnout was available.From what I see ,there is only the 8565,which comes off a straight section.If I fitted a second control box for this one turnout,can two boxes be run with enough current available?

Don't worry it won't be an issue. Control boxes don't use any current so you can have as many as you like. They are only pushbutton switches.
Also electrically operated points don't use any current either apart from during the second that they are actually changing so you can have as many of those that you like as well.
You'll be fine.