[..]I picked up a pair of mk41's to run alongside my mk4v's (>MixPre6II)[..]
If running both pairs so as to be able to compare the two and have the ability to choose whichever pair worked better each time, in general you'll want to use a stereo configuration that uses slightly less angle between mk41's, or slightly less spacing between them, in comparison to whatever configuration you like best when using the mk4v's, in order to make a recording that has similar width and imaging properties.
Once you determine what those two configurations are, Shapeways may be able to make you a single mount that supports both pairs.
If using the supercardioid mk41's to help deal with a reverberant room or challenging audience, go for less angle between mics. You can push that further if necessary by using even less angle and going wider-spaced than whatever configuration you find you like with the mk4's. The logical conclusion of this is pointing the mics directly at the outside edge of the PA (PAS) in combination with a spacing between them that is most appropriate to that particular angle and polar pattern. Pointing the mics at the PA is generally the best configuration possible when dealing with a challenging room. It does mean that you'll need a mic bar that allows adjustment of both spacing and angle. But, an alternative option to an adjustable bar when using something like the 3d printed Shapeway bars is a few different bars which aren't adjustable but collectively provide different spacing/angle combinations that are more or less appropriate to your recording position in the rooms in which you record. You might need to contact them to specify the particular spacing/angle combinations, but you can then pick the most appropriate ones.. and stack them for recording both pairs at once.
Here is the way to determine what spacing between mics is most appropriate based on the angle between the microphones when the microphones are pointed at the stacks (or outer edges of the ensemble for non-PA-amplified stuff)-
>>Improved PAS table<< If instead you want to explore making recordings in which the two pairs of microphones are mixed together, that's a whole 'nother ball of wax. Sure, you can simply try mixing them together which may or may not produce good results. But to really optimize things so as to make a better recording than either pair generally achieves on its own on a consistent basis, totally different configurations are required, different than those used for two microphones as a pair. Can help point you in the right direction if so.