Found that website...
www.afoodave.com
They are great...I post that thread because i answered someone in the forum for marshmallow so I thought it can help.
Best.

Also have a look at www.trendjumpers.de - they deliver from Germany - but delivery is fast, you can pay by paypal and the selection is quite big. They do have root beer (including diet), dew etc.
I just ordered a large amount of stuff and got everything in 4 days.

Trendjumper look ok,
they are quit expensive though, plus they are based in germany so shipping might be more expensive and you have to pay custom...
which these www.afoodave.com are based in switzerland and less expensive.
best

I'd immediately order from afoodave.com if they had diet root beer :-)

A friend of mine told me about this great website...
They have a link in the website where people can ask what they are looking for, probably when they will order food they probably are going to take what people are looking for if there is a big demand, I know that my friend got root beer with them, not diet though, and not Dr Pepper...