Craig,
I'm almost exactly your size, and will fit OK. Side to side room is a little tight with another similarly sized guy - I did such a flight in someone's RV-9A, and it wasn't bad but our shoulders were abutting. I recall our arms were a bit tight - better if he had his arm slightly forward of mine for elbow room. Also, the fuselage side sill pushes in on the opposite arm a little. His tip-up canopy certainly mitigated any tight feeling, and made my decision in seconds after dwelling on tip-up vs slider for months.
Leg room was great - make sure rudder pedals are at forward most (toward the firewall) position when you install them. Head room was fine.
On the panel, you will probably want to design it as stock and not add the lower 1-2 inch extension some people do for switches and CB's, so as to enjoy better knee clearance.
I recently flew in the slightly smaller RV-6A, and this was not enjoyable - with my head fully touching the canopy (no seat booster).
If you get a chance, try and find an RV-9 or 7 (same cockpit) relatively near you to have a sit, but note the builder's config will make it different for room - variables include the pedal position, panel height as mentioned, 3 seat back positions on the floor pan, and three seat back angle positions. Also seat cushion thickness, materials used will factor in.
But, set up correctly for YOU, there should not be any problem at your size.