As others have noted, with the addition of canards you will have to adjust your cg forward in order for the canard to operate properly; as well as adding a bit of length to the fuselage.
Now if your looking at building this a a speed plane as well that is going to take even more work. First of all you will want to get the airplane a heck of a lot lighter than even the six pound weight they suggest as the lower limit to get it to move at all. All in all your probably better just sketching up your own design base on an enforcer and going with that given the modifications your thinking of making, plus a few others like a thinner wing as well.

Now with all of that having been said,I kinda like the idea of the twin tractor powered canard, here is a sketch that some one drew from my description awhile back.