Which Xbee 900 should I use

Not sure if I am in the right place, but I have a question. I am developing a system to control Radio Control Aircraft flight line/stations. I have all the circuitry completed and software written. I have been using 8 Xbee Pros’
xbp24-awi 2.4 units. I am wanting to change the Xbee’s to 900mhz as at more than one of the flyins it will be used at there are as many as 1000 pilots registered. Our Radio systems use 2.4 ghz using channel hopping. Our Radio systems can handle up to 45 or so systems before we start to have problems with loss of control. Therefor the reason I want to change to the 900 MHz Xbees. I have been at the Digi site as well as Mouser electronic parts site and, well I am not sure what 900 MHz Xbee would be a drop in replacement for the 2.4 ghz ones I am currently using.
And with your suggestion on a replacement, do the 900 Mhz Xbees program in the same manor with the xctu software. I will need to have two groups of 8 operating within 3/4 mile of each other and they must be independent.
Any help or suggestions will be greatly appreciated as I don’t want to just jump in and order some and find out later that they wont do what I want them to.
Randy Charles

The best module option for you here is likely the XBee-PRO 900HP, which is the latest 900MHz release from Digi. It comes in the same form factor as the 2.4GHz version you’ve been using, so it will drop right in.

You can find more information on the website, and contact the technical support team if you have any more detailed questions.