Nobody could answer this I suppose, but I went and ordered the heads (smooth detail) anyway and they turned out fine:
Bothan head tacked to Antares Freeborn body & Rhodian head tacked to Mantic GCPS (early version)
:
The Quarren body is an OOP Mongoose plastic ganger with OOP plastic Skinny arms, also from Mongoose.
Comparison pics with an Imperial Assault Rebel and Legion Luke (mounted on a thin base):
T.