Honestly I feel that preamps like the bat vk-30/30SE w/phonostage are quite a bit better than the modern day arc preamps. I haven't heard the ref 2. I use a vk-5i and feel that it's in the same general league as the ref 1 which I also owned. The ref1 is far and away the best arc preamp I've heard. You might want to look at a vk-3i with a built in phono stage if you want to keep the price down.
I think bat makes the best tube preamps on market. They all mated very well with my vt100. Just my opinion and taste of course.
I heard the ls15,ls12,and demoed the older ls-5mkII. I didn't care for any of them. I didn't like the 12 and 15 at all - not enough transparency. The ls-5 had a great soundstage & I can hear why it is a classic. In my system it sounded a touch grainy, and lacked dynamics compared to the champion vk-5i. Maybe the tubes were bad - it was 8 years old or so & the solder's all looked remarkably dull and tinny. I have a feeling it had been repaired. The vk-5i easily defeated this contender.
I know you want to keep it all in one, but a decent low cost alternative would be the adcom 750 ($750 used) with a lehman black cube ($4-500 used). The black cube is physically very small. The adcom has a processor loop and can act as a passive pre. The 750 also has remote volume, active or passive mode, and a processor loop so you can run your home theater through it. A nice nice package that is sonically at the 90-95% mark of the best I've heard.
The arc ph-3 ($950 used) is an awesome tube external stage - warm and tubey yet very transparent with good bass. It's voiced with the arc house sound - big and powerful with a full, weighty midrange. Run the ph-3 into the (passive mode) adcom and you will have wonderful sound.
