Hi Ed,
I installed a pull pull system for the same reason

. I used Hitec 545 servos on the elevator and rudder but regular 425' everywhere else. I used the standard dubro system for the smoke so with the gas tank on the top tray behind the firewall, I stuck the smoke tank in the bottom. I had no issues with balance.
I'm sure the 61fx will have ample power though I'm not sure if it will preheat the oil enough for the smoke. The smoke system I installed costs about $30. Details are at
This location
To be honest I got the .91 for the sound
Best of luck and as I said, you will love this plane!!
If you have any probs, just pm me and I'll fill in if I can.
Bob