tweeter selection for 3 way ???

Hi everyone

i'm planing 3 way loudspeaker consist of:

scan speak 18W/8531G00 X2
ATC sm75-150

AS for the tweeter i'm confusing between 3 tweeters
1. scan speak 9700
2. scan speak 6600
3. vifa DX25TG05-04

xo will be 500 and 3500

can anyone tell me please the differences between them
by the sound characters :confused:

please help

best regards