which product should i use for SCADA on DH-485 network?

I have a project now.
There are 7 AB SLC 503s in the plants, i would add 2 SCADA computers to monitor the SLC 503s. I am planning to use DH-485 networking for them.

which product should i use for the computers?

1784-PKTX is too expensive, could i use 1761-net-aic or 1747-PIC,1747-UIC ?

thanks for any advice!

DH485 comms will slow exponentially as you add nodes. If your two SCADA systems are carefully configured you may not see too many delays. It might be best if you used two different networks to keep the node count low on each. That would mean a NET-AIC at each 5/03 and a DH485 bridge (or two) ar each PC.

Look here:
http://www.ind-concepts.com/Allen_Bradley_PLC_Cables.htm

About halfway down the page there is a PIC replacement for an economical DH485 bridge (real serial port required).