George's response is well-considered. I would opt for the former, where each amp handles just the left or right channel [i.e. left ch on the tweeters and right ch on the woofers]. The advantage is that the power supply of each amp is only driving one bass channel, not two. I used this method very successfully a long time ago with a pair of NAD amps and some NEAR 50 spkrs if anybody remembers those.
Let us know what spkrs you get. Good luck.
Let us know what spkrs you get. Good luck.