Another caution if you replace the wire gear with aluminum. The wire gear is designed to flex and bend in a mishap. Aluminum gear will transfer the forces to the mounts in the fuselage and is much more likely to tear up the fuselage. My suggestion would be to try the wire gear first and just bend it back when needed. Most of your gear problems will be with the nose gear anyway. You should reinforce the firewall because the nose gear will tear that out long before you ruin the main gear.

SORRY, I FORGET THAT YOU ARE PLANNING TO MAKE IT A TAIL-DRAGGER. NEVER MIND.