Integrating REL sub in to Linn aktiv system

I need to integrate my REL sub into a Linn aktiv amp set. From what I can tell there are three ways I can do it and I was wondering if anyone had a similar situation and how they resolved it:
1. Use the recommended REL neutrik cable to connect the sub to one of the bass aktiv amplifier speaker sets. The potential problem I see with this is that the sub is now connected to an amplifier that has been set for a very specific speaker set; in this case Linn Katan monitors. I would need to attach LINN BFA plugs to the end of the neutrik cable.
2. Use the REL RCA connection to run a line from one of my pre-amp outs. This would by pass the amps situation completely but now means that the sub is not �in theory� receiving the exact same signal as the monitors making for harder integration.
3. Use the REL RCA connection to run a line from the bass amplifier RCA connection out, effectively daisy chaining the REL sub amp into the Linn amplifier chain.

I have had great success using the pre out from my amplifier (your option #3). Short answer to long question though: use either option #2 or #3. Use whichever one will allow for the shortest interconnect (probably option #2).
what did you decide in the end?
i have a similar set up as your option 1, but wondered if it can be improved in any way
Hook up to your main out, then crawl around on the floor (and listen for the best sound from the sub) to try and integrate the sub(s) with the Katans. I love those speakers. I wouldn't connect to your Aktiv amp since running Aktiv is marrying the amp to the drivers. I may be wrong, but it's not worth taking chances. Maybe try Best of luck.