Thank you very much, both of you guys, you are really helpful. I think I understand now.

A bit of a thread revival. ;) It seems that my local sword dealer is going to deal with Damasteel of Sweden. Would you recommend their steel for a blade and is their basic parallel layer pattern or twist pattern (this is torsion pattern Jeroen spoke of, right?) be historical? Random from the second link also looks good to me...
Here are pages where you can see their patterns:
http://www.damasteel.com/patterns.html
http://www.ssdamascus.com/Products.html

I didn't remember that these swords were by Damasteel, thanks. They are stainless damascus, does that makes them wallhangers or are they functional?
Btw, question about the patterns still stands. ;)

This are the patterns I'm interested in:

I think that you are missing the mark a little with these pattern choices .they all look modern to me .
The first pattern is maiden hair which is a medium layer lazy twist the second is a bold version of random .
the third could look Ok depending on how you forge it down (with the edged of the layers showing on the sides of the blade it might look like piled steel.........
If you are looking for steel that will look rite for 9C then you have 2 choices (or 3).
one is to go for something that looks like piled bloomery or sheer steel , think of the patterns (and subtlety) of old Japanese blade steel and you will be close to this .
the closest modern damascus to this would be a very high layer damascus 1200layer up to 2000 layer random starts to get close but lacks the "Raw " look of old steel .
the other rout as mentioned is multi bar patternwelded construction .and there are many versions of this from quite simple to about as complicated and virtuosic as you like .
A third would be mono steel .....Polished (burnished) un etched sheer or bloomery steel looks a little bit like slightly cruddy mono steel .

There is nothing at all wrong with Making or having a modern damascus pattern on a piece based on a 9th century design ,It will not however look anything like "old " blades did .