The control surfaces will get solartex, yeah, the ailerons should be metal, but that's ok, some primer, a little sandpaper and they'll be fine. That is one critique of TF, why they didn't make simple sheeted ailerons is a bit baffling. I don't feel like tearing them apart, so fabric they will be. As provided, they'd be fine on the early MKI if only they provided the asymmetrical oil/glycol coolers. But again, it's not going to top gun, just my flying field.
Gonna power it with a DLE55RA, I have the 55 side exhaust in the Y/A XIV and it's loads of power. This one should come out lighter (than my XIV) so I suspect it'll be more like a Reno racer.
I have not fully committed to making it a MkIX, I do have a spare retract TW and could make it an early MkVIII with small rudder. First look tells me the TW unit will require some work to fit in the area provided.