I have no idea what you mean by the phrase "using HDMI over NTSC."
Depends on the way TV is broadcast in the location you are going. HDMI supports a lot of resolutions, included backwards compatibility with PAL (720x576) and NTSC (720x480), so just because you have a source with an HDMI output doesn't mean anything. However, if they are available where you / the tv is, HD broadcast resolutions *might* be the same as or at least compatible with your tv. (BBC HD is 1080i, but the resolution is 1440x1080, not 1920x1080 as in US).
By the time you pay for shipping and insurance, buy a voltage transformer, and figure all this out, wouldn't you be close to the cost of getting a PAL tv locally? Last time I watched PAL (over 10 years ago) our PAL vcr would play NTSC tapes, just vertically squished a bit. But NTSC tvs of that era didn't like PAL content.