BAT VK31SE and the VK55

Yes it mates well with the VK5i. The 55 is a wonderful amp.

I think any preamp above the 5i will mate up well. I wouldn't bother with the VK5 because the 5i was an upgrade. I had the 5i at two different times and really liked it. I borrowed a buddies VK-55 for about 3 months and absolutely loved it. Stereophile did a review on the 55 and VK3ix and gave it a very good review. I haven't heard the 3ix but I am sure its a good one.

I had a VK30 preamp hooked up to a VK500 amp and it was absolutely fantastic. Due to lifestyle changes I switched over to a VK300xSE integrated, a fine preamp/amp but not as good as the BAT seperates.

I picked up a VK-60 amp and a VK-31SE preamp. I will using my EAR 88PB. Any thoughts? Now I need racks to accomodate two tt's. That could be an expensive proposition.

I don't think the 60 is as neutral as the 55 from what I hear but thats not necessarily a bad thing. I believe the 75 evolved from the 60. Goodluck with the rack and enjoy your new purchase :)