I spent months trying to get a asic, the only ones you can buy wont make RoI.
Almost no one is willing to sell any asic for a reasonable price at least not in small amounts.
As far as trusted sites well if they arent on this website i dont consider them trustworthy.
https://www.asicminervalue.com/Just click a machine then scroll down lists all the vendors. None will be in stock thou.
Otherwise as post before says try contact manufacturer directly.