I see the 2 Allen-Bradley protocols, DF-1 & DH485, in Raco's specifications. Can I get DH+ or AB Ethernet with a Gateway?
No, You will need to use one of Allen-Bradley's protocol converters, many available as a PLC rack mounted module.
Investigate 1785-KE or 1770-KF2 and 1747-AIC or 1761-NET-AIC as examples.