Yes, an upto date PS3 will output this over HDMI, as will most HS-DVD players and Blu-ray players (I think). By upto date I mean it has had the latest firmware installed.
And yes, you need HDMI version 1.3 to do this (hence the latest firmware of the PS3).
An alternative way to do it is to use the analogue 5.1 outputs of a HD DVD or Blu-ray player (which will do the decoding) and plus these straight into any AV receiver with analogue 5.1 inputs.
LPCM is the uncompressed format (BTW DVD supports two channel LPCM, but not 5.1). Dolby True HD and dts HD MA are the two loss-free compression formats.
All amps with HDMI sound support 8 channel LPCM; you just need to find a player capable of doing the decoding. The 605 is the cheapest amp that will decode the non-loss compressed formats if streamed into it (there are HD players that can stream HD formats although they can't decode them). For the sound quality of the result, you'll need to carry out your own auditioning; just note that sound quality is not only a factor of the signal format.