Either the Magnepan LRS or MMG's (which the LRS replaced). I'd probably go with the LRS though.
Both the LRS & MMGs are 4 ohms, 86 db sensitivity.
My listening room is pretty small, 11 x 12, so I guess I'd be 7 or 8 feet away from the speakers; and I'd be running a 2.1 'music only' system, not home theater.
As far as Max SPL I have no idea how to determine that, I'm just getting into audio again. I don't crank up the volume, just listen at low or moderate levels for whatever that's worth.
Thanks
Those speakers have nominal impedance of about 3.5 ohms, combined with sensitivity of just 86 dB/2.83V/m, they are going suck a lot of current. They should still be fine with the NR1200 because of your 7 to 8 ft distance, but you would need to put a fan on top and don't crank the volume anywhere near -10. You really should go for something more powerful.
If your budget is limited to $600, the Denon AVR-X3500H is a much better alternative. Yes I know you only need 2.1 but those NR1200/DRA-800 are really rip-offs that prey on people who believe and/or prefer 2.1 receivers just because that's all they need. Just look at the images of the innards, they look ridiculously cheap.
If you can stretch your budget a little, the the AVR-X3600H is unbeatable based on its measured performance, better than the Marantz separate prepro. This way, you do it right the first time and can forget about adding any amp.