mobile

Hello, I'll start off by saying.. i didn't search the tmobile forum and I deserve any unkind words expressed for this. I am ashamed and yet i continue typing!

I just went through the process of downgrading my modem on this sprint device in order to sim unlock it. I now have a 3G t-mob signal working as expected. However, there's still a ton of sprint **** on the device. My client would like to remain stock, and thus, im wondering if I can simply load the latest t-mob stock rom on this device while maintaining functionality and, of course, the sim unlock.

If the answer is no, can anyone suggest a "stock-like" rom (kitkat/lollipop doesnt matter, she's a former iPhone user) which will meet the above requirements?

thanks in advance and i apologize for failing to search, bedtime! :)