G'Day Asi,
If I was in your position, Asi, I think I would go with the C8, with the aim to sell before I left to go OS, and aim to buy a 9.25 when I got to the states.
That way you'll get to know your way around an SCT, and probably not lose too much cash in the process...
As for the marks on the corrector plate, my scope is less than 12 months old, and I remember when I first got it, the corrector plate was so clear and blemish free that I had real trouble seeing it! But now there are little blemishes and marks all over it, and the only thing that has touched it is dew and whatever dust happens to find it's way there. I use a real gentle air blower to remove any dust I can, but based on advice I've picked up from this forum I'm resisting the temptation to wipe it. So I guess, I'm suggesting that if it has XLT coatings they are easily marked, but whether or not those marks are significant in terms of image quality you probably won't know till you test it. But I suggest the marks would have to be pretty bad before it'll worry the image...
Anyone have any better experience?
Al.