Best place to buy Extra Long Scale sets?

What specific brand and type of strings are you looking for?

Keep in mind terms like "extra long" or "long" can vary in the actual length of the string depending on which manufacturer you're dealing with.

 

Just Strings

 

The online dealer I normally deal with doesn't have every single option listed on their website like BSO did. But it's just a matter of a quick email to arrange a special order for just about anything.

 

Beware of the high shipping.

Firstly I'd contact Jason at BSO while you still can. He just got a DR shipment in and their 'normal' sets are like others 'extra long' (38" winding) so it just depends on the winding length you need.

Secondly I recommend www.stringsandbeyond.com as they also have free shipping.

 

This was exactly the point I was trying to make in post #2.

Sounds like you need a winding length of 38" (ball end to taper/silk).
I was going to suggest DR because their "long scale" is actually 38", vs. 37.25 by most other manufacturers. Also, DR strings don't have silk at the end to get in the way, either.

Ken Smith is another brand whose "long scale" is 38".

Here's the list: Bass String Lengths by Manufacturer

 

I did understand the main point of your original post.
Based on my experience during the last few years, I know most online retailers only have their best-selling items on the website; if you require anything out of the ordinary, you would have to go through a special order process, which is usually emailing back and forth.

I mentioned DR only because their standard long scale happens to be longer than most at 38" winding. Whoever carries the brand would carry what you need.