I would look at the total weight, with the 120 4C, IMO you should be about 7.5 lbs of less. You will get a solid hover and be able to learn to toque roll. The UCD 60 has the wing area to fly well at this weight. APC Prop 15 x 4 or 16 x 4 wide is a good place to start. You should have about 13 to 15 lbs of thrust. If you need to make changes to the stock kit I would not recommend going that route for your first 3D plane. IMO grab a 70 size profile like the Katana 70 or build a Mojo 60 if you want to save money. You get a great flying plane and you will not have to modify anything. I am on my second Katana and it was flying in less than 10 hours and very easy to fly. I love my UCD now only after learning to fly on the profiles. Save the UCD for your 2nd 3Der. I will always have a profile to fly 3D. I also will not give up my DO.