First and foremost, welcome! We do have a dedicated category for these sort of requests. Generally, we do have an existing feature request for specific aircraft. For the Saab and the Metroliner, the topics can be found below. All you need to do is click on each of those topics and continue your conversations and support in those perspective topics.
As for the Aero Commander, I do not see that we have a feature request for this as of yet. You would need to wait until you are a TL2 Member here on the forum. Right now, you are currently a TL0 New User and are unable to post in the #features category. Simply hanging around here on the forum and interacting on other topics will quickly reward you with the natural progression of these forum ranks.
Thanks for the understanding and have a great day!