The items I gave you links to say in stock for next day delivery in the
UK, and nothing about extended range, when I look at it. They are also
available from Farnell if you have something against RS.
If you want to know the curie temperature, that is given by the number
stamped on the back end of the tip. It is also the last digit of the
Weller part number, e.g. for a PTDD7 tip, the number is 7, which means
700F, or 370 deg C. Also, 7 is the right temperature for normal uses. 6
is too cold and 8 is too hot.
If you want to know what the shape looks like, type "PTDD7 Weller" into
google image search and you will get a lot of pictures of it. Likewise
for the other tip styles.
Anyway it sounds like you don't want the answer to your problem to be
simple, so feel free to make your own tips and heater, but don't
complain that you have to. I am certainly able to buy them, and have
them delivered tomorrow free of charge.
Chris