Bdegan,
About the only thing I did to the plane was beef up the firewall a bit with some tri stock. Originally I had a YS 140L in the plane and had so much trouble with it I had to replace it with a O.S.160 FX.

I used all the stock hardware, and it held up great through 300 flights. I would swap out the CA hinges if I had a new one though and use Robarts.

The plane is an excellent flyer, very fast and very quick, yet when landing it's very docile and will glide much better than most bipes.

I've flown the Ultimate with a Saito 180 and it is a perfect fit for the plane, stump pulling power. With the 160 it is a bit faster with a bit less verticle. I'm also running a Perry pump on mine due to the pitts muffler.

The 150 should be fine if your not into any 3D stuff. I would also spend money on good servo's to maximize it's potential.

Can I ask what you gave for the plane?