Go with YS power! BUT--don't waste your money on a DZ! The new YS 140 Sport is just over $400 at central hobbies new. I bought one and put it in my DP Ultimate and it is a great performer! I use a Pro Zinger 18x6 on Coolpower 30% and get high 8000's static. My plane uses 4 Hitec 5475HB digitals on the ailerons (MORE than enough torque) and JR 8411's on the elevator/rudder. My engine is mounted inverted with a remote glow plug and a Robart Ultra Fueler for the pressurized fuel system. The plane is a FABULOUS performer and has MORE than enough power for the weight of the plane. I started out with an open exhaust and have since switched to the Performance Specialties muffler with the rotatable exhaust positioning. It's a fabulous combination. A 20 oz fuel tank and an 1800 mAh NiCad give nice long flights with no fuss. I haven't had a single dead stick with the engine (the norm with YS) and the engine pulls the plane through easy knife edge loops on a full fuel tank. 3D type flying is easy with the throws cranked up, but I usually fly more tame flights with the plane because it is just so darn pretty in the air. The bottom line is you'll love the plane no matter what you have in it, but I definitely wouldn't waste the $$ for the DZ when you can get great performance for a couple of hundred dollars less.
Good Luck!
Ron