Hey,

Does version (U.S., U.K.) matter at all when installing both icewind dale 1 and heart of winter. Would there be any conflicts?

Since the GOG version installs with Heart of Winter (I understand Trials of the Luremaster is an option but I didn't uncheck it when I installed it), and updated to the last official patch there shouldn't be any conflicts. Since TotLM is not only an expansion but the last patch, I'd install it as well even if you don't to the expansion.