I have a Pulse 125XT that my daughter got me for christmas. Currently I'm running a Chinese 26cc gas engine in it and stock landing gear. As for balance, I have moved the stock fuel tank as far back as possible in the fuselage (under the instrument panel) with a 2200 2S lipo on a regulator in front of the fuel tank along with the ignition is the same compartment (under the hatch).

I have the servos mounted in their normal location with a 2200 3S lipo on a BEC regulator mounted to the servo plate between the servo's. The plane balances exactly where it's supposed to with no added weight anywhere.

I fly off a paved strip but I would HIGHLY suggest either different landing gear or adding some material to them to move the gear forward 1" especially if your planning on flying off grass. Landing have to be perfect otherwise you will get a prop strike (my 17" prop is now about a 16.25").

I can't say enough good about the plane/engine combo that I have. We have three of them in our club with the other two being powered by DLE20's. One has stock gear and the other has extensions where the axles were originally moving the wheels forward 1 1/2" and he has no problem taxing through the grass. I have to carry mine to the runway and start it there because trying to taxi through the grass it just becomes a half-pipe lawn mower. In the air the plane is about as perfect for sport flying as you could ask for. Not enough controls for for 3D but any advanced sport manuver is well within its ability and IMHO this plane would make a perfect second step plane for anyone wanting to move up. The 26cc is a little overpowered but thats what the throttle stick is for. I have not experienced any of the tail problems I have read about and suspect that a majority of those are caused by way more speed than the airframe was designed for. Full power dives are not what the designer had in mind and as such this plane is not intended for that type of flying. This is my new "every trip to the field " plane that goes regarless of what else I'm taking. I left the wings in two pieces and use the pins/wing bolts to hold it together as does one of the others flying at my club, so far no issues with the airframe on either. The wing is fat but the fuselage is very skinny so slowing down for landing requires so pre-planning otherwise it will float the full length of the runway and finally land in the next township.

Here's a link to the 125XT thread where I posted some pictures of my build.

<font color="#0000ff">http://www.rcuniverse.com/forum/fb.asp?m=10897447</font>

As for your original question about the 60 size with a DLE 20, In my opinion you would be way over-powered and have a lot issues to work through getting it to balance, getting enough prop clearance and keeping the vibration damage to a minimum. The 125 would be a lot better suited since there's about twice the airframe to dissipate the vibration and prop clearance in stock form is enough to get you flying and finally getting it to balance will not require a bunch of lead in the tail (which equals more speed which equals longer takeoff runs, longer final approaches and higher stall speed).