MrT, there may be another way to do this. The Quad has a low impedance at high frequencies and a lot of transistor amps will tend to make more power due to that, part of the reason why they sound bright on the ESLs and with less bass impact than most tube amps.
OTOH, your Maggies have a flat impedance curve, but also need some power, but delivered into a 4 ohm load. With any SS amp made, the more current you demand of the amp, the more you get non-linearities caused by capacitive elements in the junctions of the output devices. IOW even though they may drive 4 ohms just fine, most transistor amps will sound better on 8 or 16 all other things being equal.
So there is a single solution that might be worth pursuing, the ZERO. If you use a transistor amp, this may take away some of the glare, although you will also loose power. But with a tube amp it may not only have the amp sounding more relaxed, but may give you greater power (although only slightly so) as well.
Some of the driving issues with tubes and Maggies are actually the speaker cables. The ZERO will allow the cable and the amp to see 16 ohms, and then a very short set of cables can be used on the 4 ohms side, allowing you to keep your cable losses to a minimum.
Something to think about.