Best BB for 1 joule VSR

Hi,
I play in Italy, max 1Joule for everyone.
My build has a Psionic Upgrades inner barrel and hop-up, which is considered the best in class here in italy.
Their technology says that the set works best with BB's between 0,30 and 0,4.
However, I think 0,38/0,40 is pretty weight for only 1 joule (correct me if I'm wrong) I was thinking to use bbs between 0,3 and 0,36.
I heard that BLS are the best, but I can't find many resellers in Italy.
The next best are Novritsch, so I was thinking to go for them.
If you have any other good brand (better than Novritsch or BLS), easily accessible in europe please let me know.
However, since I will pay a quite expensive delivery I would like to order just one weight, if there is one which would the "best". Which weight do you recommend for such weak spring? Or I need to try all the BB's between 0,3 and 0,4 and find the best myself?

Thank you.