[crisdiaz01]

Even if tmobile doesn't officially get the 735 or 830, will those phones still be able to work with tmobiles network bands? That way, I can just buy a factory unlocked version and insert my tmobile sim.

[xandros9]

Any will definitely work.
The question becomes how well. You'll probably definitely get 2G/EDGE data, maybe 3G in some refarmed regions, but as for3G/LTE normally, I dont know off the top of my head.

[RumoredNow]

Either one is not optimal.

Nokia Lumia 735 vs. Nokia Lumia 830 - GSMArena.com

No 1700 MHz on the 3G/H+ radio or the LTE. In T-Mo LTE areas that means you would possibly get H+ on 1900 MHz, but outside LTE areas H+ is on that 1700 frequency so you would drop back to EDGE speed on the 2G radio at 1900... No LTE possible on T-Mo with either one.

[Manuel Larson]

I'm going to try Blu 5", It said up to 1800 Mhz, we'll see what Amazon sends me

[RumoredNow]

I'm going to try Blu 5", It said up to 1800 Mhz, we'll see what Amazon sends me

For T-Mobile US?

Up to 1800 is meaningless. The radios are pegged to certain frequencies, usually more than one. It's not really an oscillating receiver even though there is some dynamic range at each setting.

Here's the spec on Blu Win HD: BLU Win HD - Full phone specifications

​The W510U would be suitable for T-Mobile H+ and the W510L for AT&T H+...