Looks good Richard,
It looks similar to the hilleberg Unna,, but with a vestibule,
As rajboy says there will be a long waiting time, unless he has one in stock,
We had a TT Drift custom, waited ages for it,
We used it for about 2 years, probably done about 90 to 100 wild camps, we were happy with it,
The back of the tent does look like it would suffer in high wind, as you said the guy out point doesn't appear to be reenforced
You could email or phone Mark and ask him, it does say the fabric has an 18kg tear strength.
I notice it doesn't appear to give the overall height on the website,
Please keep us informed if you do get the tent, I would be interested in one maybe
Ask fox for advice, he's an expert with trekkertent