IMO isolation transformer is a wrong route. It is fine for stuff that doesn't need a lot of current - DACs, CDPs or the TT you mentioned. Then you can easily get sth with multiple VA rating of your unit.
For a pair of BAT monos, you would need a 4-5kV one, if sound quality is not to be significantly compromised. 5kV transformer is neither cheap, nor silent (you would have to move it into another room).
For a pair of BAT monos, you would need a 4-5kV one, if sound quality is not to be significantly compromised. 5kV transformer is neither cheap, nor silent (you would have to move it into another room).