SACD or DVD Audio, which one is winning the race?

Why pick sides? Go with both using low cost equipment until the dust settles. Even a low cost DVD-A gets you 24bit 96Khz, which in practice seems as good as the SACD DSD coding. (Actually in either case the sound quality depends mostly on how the disc was mastered). For one thing, at the present time you need access to both catalogs of media.

The stereo program on SACDs is an AREA of the disc, not a layer. The layer idea (Hybrid SACD only) relates to a media that can be read by regular CD players.

At present a DVD-A disc does not have a stereo program although
(1) the player can do a realtime mixdown
(2) I heard a rumor that the DVD-A spec was being revised to provide for a stereo program.

In my earlier comment I said "low cost equipment" instead of "Pioneer DV-45A". (I, and others familiar with this unit, were starting to sound like a broken record).

Is there any other $400 player that does it all?

At the moment there do seem to be more SACDs than DVD-A, but the best discs I have obtained happen to be DVD-A. Both can be good or bad depending on mastering. You need both.