will these phones work

[pigisstuipid]

so i am new to tmobile and just signed a value contract and i was looking for a unlocked phones
i know that the frequency has to be 1700 for it to work on 3g and 4g so will these phones work

will this one work on tmobile 4g becasue it lists the 3g frequency as 1700 but doesn't say anything about 4g and i know that these are 4g phones
gsmarena.com/sony_xperia_t-4899.php
or
gsmarena.com/sony_xperia_ion_hspa-4798.php

and will this work on 4g or 3g
gsmarena.com/nokia_lumia_710-4276.php

and where can i find good prices on unlocked phones other than newegg and amazon

i also found this thread which talks about different versions and the one on amazon is different fro m the gsmarena ones
forum.xda-developers.com/showthread.php?t=1841920

amazon.com/gp/product/B0088LHJXY/ref=gno_cart_title_1

as you can see the amazon is lt28i and the gsm is lt28h and i cant find the lt28h so do you think the lt28i will work on tmobile 3g and 4g

 

[aurora40]

T-Mobile sells a Lumia 710. So if you get the T-Mobile one, it obviously will work on T-Mobile. You can get it new for $250 and get a $50 refill card, making it effectively only $200.

I don't believe either of those Sony phones will work, except with 2G data speeds.

3G and 4G on T-Mobile are the same, if the phone doesn't support the 1700 band on UMTS/HSPA, you won't have any decent data with it.