Chilli, re your question, take a few minutes and read the link below. No idea how old it is or where I found it, but I’ve kept it because its one of the best summaries I’ve seen about the technical considerations in selecting truly efficient speakers. There aren’t many models to choose from so it can be a challenge, but it is well worth the effort. Good luck.
https://www.dhtrob.com/overige/tubefriendly_lsp_en.php
https://www.dhtrob.com/overige/tubefriendly_lsp_en.php