best antenna 5.7 & 900

Whats the best antenna at any price, we are working on SCADA, price not a big issue (within reason)

No questions asked and no price tag?

Anything made by kathrein-scala for the 900MHz SCADA.

M2 antenna or the 15db parabalic grid antenna by pacwireless

on AP side ANTEL omni (900Mhz)

advanced antenna on the 5.7 has worked great for me…