Reccomendations Sought for Cellular Modem (standalone or bridge mode available)

I am planning on adding failover and load balancing to my networking setup. I am using a Nighthawk RS700 as the router and a TPLink 707 as a bridge solely for its failover and load balancing features (i.e., with its router features disabled). I am looking at T-Mobile cellular as the failover bandwidth source. To do this, I cannot use T-Mobile's equipment, because they use an integrated modem/router and the router functions cannot be disabled. I am looking at the Netgear LM1200, which would fit the bill perfectly, except that, per the website description, throughput seems to be limited to 150Mps. I would prefer something that will allow for more bandwidth, but essentially everything I find has an integrated router. I can live with the integrated router provided I can disable it/utilize bridge mode and not have it interfere with the "real" router. Any suggestions or opinions on the LM1200 or a more robust option would be greatly appreciated.

P.S.--I just cannot see spending the money for the $800+ cradlepopints I came across.