Linn- Ekos or PS Audio 300

Get the lingo - the improvement is not subtle. I heard 2 lp12s (lingo-ed and not) side by side and the lingo extended the bass by what seemed to be an entire octave. The psa (which I also have) is great and you definitely want power treatment for your digital stuff, but it's still more subtle than the lingo. And, as has been pointed out, the psa is irrelevant if you get the lingo anyway.

I would also go with the Lingo. If you determine to add the PSA 300 later, great. My experience with the Lingo is that plugging it into a power conditioner makes very little difference. I have not tried the PSA, but I have tried other PLC's and PC's too with the Lingo and it was not worth it. Both the Lingo and the PSA are regenerators, so it would be redundant. The PSA may be great for your preamp and digital front end, but it probably won't do much for the Lingo. With a Lingo on the LP12 and the PSA on the rest of your front end, however, your system will be transformed (no pun intended), you'll be up late listening, daydreaming at work about staying up late listening, ... wait a minute, I'm the one daydreaming at work already.

I have had all this gear at one time or another. The Lingo makes a big improvement in sound and gives you 45rpm. I'd go with the Lingo. You can't use the multiwave option with the PS if you plug your LP 12 into it. If you go with the Lingo now you can add the PS down the road and have it all.

I had an Arkiv and a Ruby 2 in my Ekos. The Ruby is warmer, tracks much better and is cheaper to retip. This one is hard to call without knowing what your priorities are. I prefer the Benz but that was in my system which can be a bit bright.