Yea, as I recall doing this a few years back, there aren't a lot of options in 28mm, or 25mm scale either, which is a shame.
Seems like a good opportunity for someone to create one or more ranges/factions in suits.
Crooked Dice also does some Space 1999 astronauts too.
There are also the "not-Trek" minis in more streamlined spacesuits, produced by Victory Force. Looks like the owner was trying to sell the business some years back, and there doesn't seem to be a lot of activity there on the website, given the date of the last update.
Prices seem rather high to me, but they used to offer good sales occasionally. If you don't need too many, perhaps that is an option too.
Alas, doesn't seem like the Clix manufacturers are interested in astronauts either, which is also a shame.
