I had wheels on my version that had the axle glued into the bottom of the nose. It flew but it could not rotate on take off! You will need to ensure that the tail boom can swing downwards on take off because without rotation is takes a long take off run to get airborne. Otherwise it was fine!
I don't mean to knock your idea, but putting landing gear is not going to help if the model is underpowered. If anything the extra weight will make it worse. Get hold of an appropriate prop. Hand launching an explorer is very easy. It should almost fly out of your hand.
It will fly fine, just be sure to check your control directions, prop nut, control function and CG - BEFORE you try and fly it, then give it a really positive throw, nose slightly up, with plenty of throttle.