I am not sure what are the pros/cons of using the different toolchains and I am by no means an expert in this embedded stuff, but I found the CodeSourcery's compilers to be very simple to setup and use. You can download from
here. The flags that should be used when compiling for DX and K3 are "
-mcpu=arm1136jf-s -mfpu=vfp -mfloat-abi=softfp".