Isn't i386 just a different way of saying x86/32bit, right?(More or less)
What you really need to do is just force your compiler to compile CSFML as 32 bit shared libraries. You can do so by adding in the extra GCC switch "-m32" when you are generating the makefiles with CMake.
I don't have CMake on this computer, but I think you would add it to the CFLAGS field and then configure/generate and build like usual.