Kyocera Cyclops K325 / K312
Only CDMA 1900?
Virgin/Sprint do use the 800MHz band right?
Sprint's current, native CDMA network is 1900-only.
Sprint does offer 850 roaming on carriers like Verizon for its own customers, but Virgin does not have such roaming agreements, so there is no need for 850 on a Virgin phone.
The Slice is also a 1900-only phone: