Search for ROMs here:
One Android Development - xda-developers
Unfortunately a lot of ROMs do not work on the Sprint version of the HTC One, so you're going to have to read every ROMs thread very carefully in order to find out whether or not it is compatible. Spring seems to have compatibility issues with custom ROMs and modifications, so you might find it a bit hard.
These are my favorites:
Android Revolution HD
TrickDroid
RGUI
TeamVenom's Viper ROM
I have seen a lot of modifications regarding transparent statusbars and widgets, you're going to have to look here:
One Themes and Apps - xda-developers
As I said, try and find if they work on Sprint devices or not, and which base (4.1.2 or 4.2.2) they work on. Each modification has different requirements.
Read the instructions and see if they'd work on Sprint. Good luck man.