Best amps to use for the Dali megalines

Hi All

I know this has been discussed before, but I would be very grateful for some advice re the Dali Megalines. I have a set od Dali's coming with the TAD tube crossovers, and at present have 2 Audio research REF 750's to drive the one set, but need to get a second set of amps and was thinking more along solid state lines. Would one use the 750's for the base and midrange or the tweeters, and what SS amp can you recommend? Thanks