I believe that your bass has a 35" scale which does not
necessarily require Extra Long strings. According to D'Addario, here's how to measure string scale:
1) Mark the lowest pitched string at the nut with a marker
2) Remove the string and measure the distance from the inner edge of the ball end to the mark (that you made in item 1). Record this length (it's your string scale) and refer to the chart below
up to 32" short scale
32" - 34" medium scale
34" - 36" long scale
36" - 38" super long scale
Again, this is D'Addario's criteria, but you get the point.
In the event that you do need extra long strings, they shouldn't be terribly hard to get. Though you might have to buy 'em online.
Tom