I have the BME 44 gasser in mine and it is perfect. The BME 50 would be even better. To use the rear intake ZDZ 40 you'll have to open a hole for the carb in back of the firewall.
I have close up pic of my BME engine installation in the Patrick. The web page is at
http://www.devino.org/mark/airplanepics/dp330l.htm
-Cheech