Is it possible to use something like this:
http://www.aliexpress.com/store/product ... 25216.html
(or something else that has SIM slots on miniPCI-e card)
with RB433UL?
Or do I have to get RB953GS-5HnT-RP with two SIM slots onboard? Are the SIM slots on motherboard a requirement?

I'd prefer RB433UL as I could add 2.4GHz wireless card and it's a bit cheaper. Also the outdoor case fits 433 but not 953 from what I understood. I'm looking to build ~40 routers with 3G/4G broadbands from two different carriers.

Does anyone have recommendations for 3G/(or 4G) modem? List of the supported devices is so long that it's hard to guess which one would be good

Thanks

You could use a mini-pcie to USB adapter with a sim slot such as this one.
http://www.ebay.com/itm/like/1817254821 ... =82&chn=ps

I've been playing with an ericsson F5521GW modem and have it working with a 951ui-2hnd in the usb slot. Not all the information on the info channel is readable by rOS; such as signal strength but the modem works and connects. I'm using ATT in the US.