Running orbot with garnet or amethyst in combination with amber works pretty well for me.

Here is a list of onion relays:

nostr:naddr1qqxnzde3xserjdfjxvurjvp4qgst94nsmefmya53crp5qq39kewrtgndqcynhnzp7j8lcu0qjple6jsrqsqqqa28tdea8t

Or on github:

https://github.com/0xtrr/onion-service-nostr-relays