The Auron SMS products should work with almost any GSM modem that supports AT commands for sending SMS messages. That said, these are a couple of GSM modems that we have experience with or that we have seen work with some of our customers.
Find information about how to setup a GSM modem for use with any Auron SMS product.

Gemalto EHS6T
Quad Band
EDGE, GPRS, GSM, HSDPA, HSPA, HSUPA, UMTS
Supply Voltage Range : 8 V to 30 V
Dimensions : 115 mm x 86 mm x 26 mm
Operating Temperature : -30°C to +65°C

CInterion BGS2T
Quad Band
GPRS, GSM
Supply Voltage Range : 8 V to 30 V
Dimensions : 55 mm x 80 mm x 23 mm
Operating Temperature : -30°C to +85°C

CInterion MC55iT
Quad Band
GPRS, GSM
Supply Voltage Range : 8 V to 30 V
Dimensions : 65 mm x 74 mm x 33 mm
Operating Temperature : -30°C to +75°C