You probably can't go wrong with any of those 3 choices. I also have a BAT VK-P5 w/ $1200 worth of mods from Great Northern Sound. I'd be interested in hearing your impressions on the six pack upgrade. I'm currently using a Helikon on my VPI HW-19 mk IV w/ SAMA table and JMW 10.5 arm. I also have the SDS. I'm very pleased with the sound of the Helikon, very detailed, yet non-fatiguing. I have heard the other cartridges, and they did sound very good also, but I haven't heard them in my system. Like I said before, I don't think you can make a bad choice out of these 3 cartridges.
Regards,
John
Regards,
John