John Sayers' Recording Studio Design Forum

Hello im new to this forum, so i apologize if anything im saying has been covered.

I have a studio in scotland SD(cold winters,Hot summers). I use baseboard heaters in the winters, and now i'm trying to figure out my HVAC system for air conditioning. I'm planning on doing the duct work myself.
I'm lining duct work with one inch foam.

Now here is my questions. I have a 20x20 foot liveroom, 14 x 25 foot Control room, and 8 by 8 iso room.
So obviously the iso room is gonna be hot real fast when someone is in there.
The control room is always warm, (5plus dudes, gear ect.)
Live room is not nearly as much of a problem. One dude for a few hrs at a time.

What do i need to do to have each room comfortable?
I'm looking at $4000 budget.

I was thinking about just putting the iso room and control rooom on one thermostat and the live room on one thermostat. with a zoning blower system.
And just putting a supply to the iso room and no return. (is this stupid)?
If i do the zoning idea how do i need to run my send and return?? HELP!!!