I'd just the best mastering, even if it may be redbook. Like Dreadhead I don't place much stock in high res, the mastering will make a much bigger difference (compression, EQ, etc).
There are a couple of ways to convert the DSD to PCM. One is using an older Oppo DVD player and another is the PS3 method.
See how HDTracks does it: https://www.hdtracks...DSD_to_LPCM.pdf
While I can appreciate that HDTracks are proactive about taking down upsampled lower res being sold as high res (at least from what I have read), I don't find them completely innocent in that they must have some suspicion when they offer these files for sale.