Hi

I have a Midwest Super Stinker that is ready to fly with a YS 140 DZ . The plane is well on balance. The total weight is 12 lbs. It is quite expensive to run those engines, specially here in Denmark so I would like to place a GASSER on this one. I never has one before.
The RTF weight for this plane according to spec. is 12.5lbs-14 lbs , so I think I can afford weight. Mine is only about 12 lbs dry RTF. So I have room up to 14 lbs, considering that we have to add the weight of the actual engine, which is 2 lbs. In theory, I could go up to a 4,5 lbs. engine.
I have a short list of several gassers that I think are the most appropriated for nice aerobatics and vertical performance, but I am not sure because I never tried before:

1- DA 50
2- 50 zdz
3- 40 zdz
4- ?

Super Stinker spec.

Wingspan (top wing): 60"
Wingspan (bottom wing): 58.5"
Wing Area: 1240 sq in
Ailerons on top and bottom wings
Airfoil: Fully-Symmetrical, Bi-Wings
Length: 59"
Weight: 12.5 - 14 lbs

I have room for 20" or a little more prop, but I can always place 3 blade anyway.
HELP PLEASE