Need amp advice for Martin Logan Preface , Vignette

[young21]

Hi !

I recently purchased ML preface for Front LR and Vignette for center and rear.
These will be part of my basement home theater setup in a hall 20'Lx12'W.
BB suggested ONKYO SR707 will be just fine but I am not sure about load of the 4 ohm Preface and 6 ohm Vignettes will put on 707. BB also mentions the ONKYO 707 will convert internally to support the 4 ohms. I was getting some other suggestions that Rotel 1560 might be the amp for these MLs.

Given the cost difference of 707 vs 1560, I am not sure what's the right combo for $$ and equipment for typical home theater usage for watching movies primarily.

Is Vignette the right choice for center channel or should I be getting something more focussed for the center channel ...

What's a decent receiver to start enjoying the ML speakers ?

Thanks in advance.