I also suggest the Pioneer, but not simply an Elite series. Look into the VSX-1014. Many of the top-of-the-line 'regular' series of Pioneer VSX series receivers are simply last year’s Elite series units :-)
Most [of the top-of-their-line], receivers from any manufacturer are able to run 4-Ohm loads without any issue, no matter what the specs might initially suggest. I am currently running an older Technics SA-DA10 receiver into a set of Magnepan 4-Ohm fronts, 6-Ohm center, 6-Ohm rears and sub simultaneously! This setup will play loud enough to deafen without ever forcing the receiver into shutdown, enter protection mode or audibly distort. This from a measly receiver rated at a seemingly anemic 100-watts per channel, (at 8-Ohms), $500.00 receiver!
Andrew D.