Samsung Galaxy S4 i545 will work on RUIM if the bootloader is MDK or ME7 with Hyperdrive custom ROM. Samsung Galaxy S4 R970 will work on RUIM with data upto bootloader MD9. All those phones above the specific bootloaders are CSC strapped.
http://forum.xda-developers.com/showthread.php?t=2559335 This CM ROM will work on L720, I545 on GSM, NV and RUIM with data.
GalaxyS4/SCH-i545/roms/JellyBeans/jfltevzw_JellyBeans_B5.zip This ROM works on RUIM with data with MDK modem.