there is only one problem of using European Amigas in USA (other than 220V), if you're gonna connect it to TV, it will
need one with support PAL system. oh wait a min.. IIRC, you can switch to NTSC in early startup menu. so that might not be a problem. I think there is a hardware hack on aminet for NTSC/PAL switch.
BTW, if you have enough money go for A1, just check first if it runs UAE.