2. HDMI requires v1.3 to have the bandwidth.
Not true. HDMI 1.2 has enough bandwidth to pass decoded (i.e. PCM) TrueHD audio.
HDMI1.3 is needed to support encoded TrueHD (i.e. passing through what's on the Disc). You're correct when you say that if you went this route you'd need an amp with TrueHD decoding to get the signal. There are some about, but not many - the denon AVR4308Ci is an example of one which does, i believe.
GFX cards with HDMI audio support onboard (as opposed to re-routed spdif) are also pretty thin on the ground. i think the radeon 2x000 series are the only ones which do it at the moment, but even they will only support 5.1 dolby/aac (spdif).
cyberlink powerdvd will decode trueHD to 192Khz analog, but onboard mobo sound will not do this justice, imo.
go for an auzentech (one of these -
http://www.auzentech.com/site/products/x-meridian.php).
this will give you 5.1 or 7.1 (most HD discs still only have 5.1 soundtracks) very clean, high quality and loud analog sound which can go to your amp in analog.
the holy grail afaik is 7.1 lpcm carried on the same hdmi as the video, but there's no products i'm aware of which will do this straight from your PC.