dwagonade

So I bought this gun a little over a week ago and it just came in today. I absolutely love it and I cant wait to take it out on the field but I want to get some optics for it. I haven't been able to find any WE brand SUSAT scopes in my area and I was wondering if anyone knew of some 20mm picatinny adapter rails that would fit on the 18mm dovetail. I did quite a few google searches but so far I my searches have been less than fruitful, any feedback would be great, thanks