Accessories Looking for an Unlocked International SIM-based "MiFi"

[gtbarry]

I'm on t-mobile USA and want to take an unlocked "MiFi" device with me when I travel overseas. This way I can leave my t-mobile USA SIM in my phone and receive free text messages. But then I can buy a local SIM to insert into my "MiFi" for a higher speed connection for data than I get with the free t-mobile international roaming data.

I want a "MiFi" that:
- is unlocked and can fit a variety of SIM's
- is long lasting battery and charges via micro-USB (just like my phone)
- not too big or heavy

Any recommendations are appreciated

Thanks!