New Integrated amp recommendation

Greetings:

I’m looking to upgrade my Yamaha 801 to drive my Revel 328s

Unfortunately I live in South Carolina and auditioning equipment requires a fair amount of time and travel. 
The room is 20x25 loft open to one side to a staircase and 11 foot ceilings (not ideal but limited amount of conditioning will follow) 

Almost always classic rock and contemporary jazz never above 80db Vinyl/CD and streaming

I’ve read a number outstanding reviews on Luxman integrateds and that is the first question..Is the 505z a good fit? If so does stretching the budget to the 507z offer a sonic difference? If not Luxman any other recommendations. I’m not necessarily looking to color the sound of the Revels but the Yamaha and maybe the room lack a bit of low end clarity and maybe a bit of fatigue from the Be tweeters.

Finally has anyone had experience buying direct from Japan? Can I assume the transformer is going to add unwanted noise?

Appreciate any thoughts love the forum. Learn from it everyday.

Thank you

JF