Hi,
Yes, I think the 3M-140 would be nice for an Enigma. It should have comparable power to an OS-140RX. Actually I think the 3M-140 is also more than enough for the Rhapsody, but compared to the Synergy I think the Rhapsody is the most power hungry... That is the reason behind my thinking.
I actually have a Dingo in my closet which was meant for the Synergy, but I don't like the fact that you need to run 25%-30% of nitro... It's expensive stuff!!!
The wing fixing on the PL-Prod planes is done using a nylon screw in the root rib and the nylon "wing" nuts you can see on the picture in my last post. I wondered for a while where they got these nuts, which seem ideal for this purpose, until one of my friends told me that it was toilet seat hold down nuts........... I checked on my own toilet, and he was correct.
I have attached a picture showing the root rib on one of PL-Prods planes. As you can see the screws are spaced evenly on either side of the wing tube.