If you are waiting that it shows "in stock" then you probably could wait forever
Most of the products from aquacomputer are produced on order so to say, if you want something then just order it. Then it should arrive at your place in the shown lead time.
If you can't wait that long then the only solution would be to check some onlineshops if they have it in stock.
(aquatuning for example if they are shipping to your country.)