........ I can see that for this kind of sim, pedals for yaw (and probably a flight yoke) are likely preferable to a stick with twist, ........
Pedals are definitely worth investing in as you need yaw for proper aerodynamic control - which is why I don't use my pedals in Elite as that flight is completely different and using pedals in that really messed with my flight sim co-ordination. If you progress on to helicopters then pedals are essential really.
There is no need to buy a yoke, since you have a really good stick then that will serve for all aircraft (lock off the twist when you get pedals). Choppers, Airbus, fighters and many newer aircraft use sticks anyway.
I don't know the availability of pedals at the moment - I have CH Pro pedals and think they are great (built to last), maybe the cheaper Thustmaster T-Flight ones will do the job, I don't know but Logitech now make what were the Saitek ones. There is no need to go forking out for things like Crosswinds or the expensive Thrustmaster as you really just want something robust enough to give you three axes and not break when you kick it by accident.