Just my opinion, but wanting to fly @ your weight of 242#, having 8 gallons of fuel available, & flying off of grass, the 503 & G10 don't have enough horses to fly a gyro well @ all. The 532 possibly, if you can stand the power band in the critical phase of taking off as well as flying around in cruise rpms.
This is assuming the G10 is the 3 cylinder, 1,000cc Suzuki automobile engine. Supposedly putting out about 60 hp. The extra horses it puts out over the 503 is negated by the weight of it being a 4 stroke engine.
The "coming on" of power of the 532 in the rpms just when you want to cruise around, and particularly annoying, when you are nursing up the rotorblades to flying speed prior to lifting off. Sudden jump in rpms makes for too much airspeed, which results in too much air flow introduced into the rotorblade disc, causing them to quickly flap, which onsets so fast that cutting throttle & moving the stick forward to level the disc is immediately required to avoid damage.
I don't have the experience of flying an 532, but have heard of other's problems in this area. I do have experience in flying a gyro w/ the 503. Weighing about same as you, w/ the same amount of fuel, it is painfully lacking in reserve power. This is near sea level. A 503 on a gyro works much better w/ a pilot @ considerably less weight, as well as carrying less fuel. I found the 503 was fine as long as I kept the fuel around 2-3 gallons. This was flying a set of 25' rotors. Apparently, trying to carry those extra 5 gallons was past the tipping point of having peppy engine performance vs. flying a slow dog.
Any 2 stroke engine in this hp range gets about half the distance in fuel consumption flying a gyro than trikes or light airplanes, due to the huge amount of drag created by the rotorblades to fly around on. The trike wing & airplane wing is about twice more efficient due to the wings.
The trade-off w/ flying rotorblades on a gyro is the lack of dangers of stalling. Extremely more maneuverability, too. Ease of transporting a gyro on a small trailer & little time required to assemble & mount the rotorblades, compared to the time needed to get the trike wing ready to fly & then to disassemble afterwards to "unfly". All that isn't a problem if you can fly out of wherever you store your trike, airplane, or gyroplane.
When I switched to the Yamaha snowmobile engine (3 cyl. 998cc, carbed), all those problems regarding lack of power & ability to lift my weight & to carry 8 gallons of fuel went away. Excess power. I don't even use all that is available.
It actually scares me to leave in full throttle for more than lifting off & climbing out a few hundred feet, because of the speed that builds so quickly! I want to live to be an old pilot, & don't care about being a bold pilot!
And, due to the pitch of the prop (about 13 degrees), I don't use more than 90 hp. That Yamaha engine is rated by them @ 115 hp. Redline is 10,500 rpms. My prop-limited rpms are 7,200.
I have flown it to 100 mph, where I chickened out, because of how much I could see the rotor disc was down in front of me to achieve that speed. I was wondering where the line was in terms of the rotorblades tucking under the airflow. In an open frame gyro, flying @ that speed, there is tremendous airflow trying to remove your helmet & press you back into the seat. Uncomfortable.
It is much more enjoyable to fly along in an open frame gyro @ 45 mph-55 mph. Feels just right. In the groove, just like driving a motorcycle on a fine day! Probably just like flying a trike, from what I've heard speaking w/ trike pilots!
Flying along @ those cruising speeds, the Yamaha 4 stroke engine uses less fuel than a two stroke. No 2 stroke oil used, & using regular octane gas, vs. premium gas & a good-quality 2 stroke oil highly recommended for 2 strokes.