If you're interested, the hifi news reviewer of the M10 back in '83 tried a few pre amps, namely the 101, the Zebra, DNM Primus and Burmester 838. He liked them in that order with the DNM and Burmester a well ahead of the Meridian ones and with the Burmester really showing what they could do..
I've just recently picked up a pair of M10s (need the leads soldering back on to the boards and they've mis-matched tweeters, different versions of the T33) so after some light restoration I'll be experimenting with pre-amps soon too.
The M10 amps are full, double paired transistor 105s but with bigger transformers and caps than I think could fit in a 105 case, two amps per speaker - two channels of one amp feeding the four bass units and the other split between mid and treble.
Shielded, twisted pair... sounds like CAT5 cable to me, pence per metre. CAT6 (properly designed for gigabit ethernet) might be higher purity copper. A suggestion anyway, if not against the ethos of most audiophiles.