Ready to commit - not sure on used or new?

[GraemeP]

I have been keeping an eye out on a number of time pieces that float my boat - namely:

IWC 3717 - bit out of my price range, seem to be a lot of different models under this
Sinn - a number of different models, but gravitating towards 356 auto with sapphire & 756 Diapal
Omega Aqua Terra - found a used one for £900 but unsure about size (this is an issue all round for me without trying things on! I am what you might call athletic at about 5'9 and 10.5 stone.
Omega Rail Master - these seem very similar to the AT??
Omega Sea Master Planet Ocean - non chronograph, probably the 42mm size
Tag Heuer Monza (obviously second hand) Chronograph (either a re-edition Heuer or a late Tag Heuer).

I can no longer view for sale ads on TZ so don't know what is available. I am thinking along the lines of a new Sinn or Planet Ocean (if I can find a good deal), or any of the others used. Can anyone tell me if there is anything above on TZ available, or advise best places to get the Planet Ocean?

I would use Chronomaster for the Sinn.

Thanks all in advance!