One of the cheap Haoye EDF units ... think it's the 51mm has both intake and efflux addition rings ... I know they work well having used them.
My Concorde improved when I 'tubed' the efflux after trying with the square bare nacelle units. I haven't 'tubed' the intake as she now flies ok on 4S ...
I used 3mm Depron rolled round and then just simple taped in place .. rough but works.
I have to admit that I am looking at this as a project :
FW 1000x1000x1000 Bomber.
An interesting and sleek looking machine.