Ok, I measured the tanks and came out with this:

Small Tank: 24oz.
Large Tanks: 76oz. each

Total: 76+76+24= 176oz.

Without the small tank you have 152 oz. At full power the P-200 draws 24oz. per minute. With just the 2 main tanks you would have 6.3 minutes of flight time with a full UAT left. Add just another minute of flight time if you keep the small tank. Now you wont be flying at full power the whole time obviously so lets say you are averaging 18 oz. per minute, then you have 8.44 minutes of flight time on just the 2 main tanks.

Based on this I would go with just the 2 main tanks, I don't see the need for the third tank plus the fact that all that weight is forward of the CG and will be draining off so the CG will shift in flight. Up to you though Dantley.