OP--See Almarg's note above. I think you are going to be fine with the impedance matching, as long as your pre doesn't spike too much in the low frequency. You have a very solid trial period with SVS. Let your ears judge. Sounds like you know what you are looking/hearing for, and, if you don't find it, you know what to do.
Your biggest hurdle is probably going to be placement/integration, especially if you need a large "sweet" spot.