Are you sure you are going to married with FLAC+ReClock permanently? If you decide to upgrade GPU and AVR and try bitstreaming, perhaps you will find how easy and great bitstreaming is and will be thankful that you ripped all BDs with compressed HD audio intact. For example, are you still decoding AC3/DTS to LPCM at ripping? Almost nobody decode AC3/DTS at ripping because bitreaming AC3/DTS is much easier than decoding them to LPCM first in PC, then send LPCM to AVR; this assures bit-perfect sound/perfect channel mapping without being bothered with Windows Audio Engine (one of the worst Windows components for HTPC). Exactly the same applies to compressed HD audio codecs.
I highly recommend keeping all video/audio/subtitle streams intact:
- H.264/VC-1/MPEG-2 -> H.264/VC-1/MPEG-2
- TrueHD/DD+/DTS-HD MA/HRA -> TrueHD/DD+/DTS-HD MA/HRA
- PGS subtitles -> PGS subtitles
(use for example MakeMKV or BluRip). This assures the best quality and the best future-proof. If your current hardware supports only multichannel LPCM, don't worry, decoding HD audio to LPCM bit-perfect in real time is one of the easiest tasks.
Sticking to the obsolete method just because you don't want to try a new method with better filters (LAV Splitter and LAV Audio Decoder in this case) is really a bad idea, IMO. Software/hardware are developing everyday.