Region coding (ie, Regions 0-6) and video format (eg NTSC or PAL) are completely seperate things. The major movie studios insisted on a way to dictate how movies were released on DVD, so they could stagger release dates across different regions, etc. This led to the regional coding system, although most DVD players can be easily modified to circumvent this. If you buy DVDs in the US you need to ensure that (a) your DVD player is multi-region, and (b) your TV set can display NTSC or PAL-60 (fake PAL) signals. A third issue is whether your multi-region player can handle RCE discs.
Whenever I've looked in shops in Orlando I've always thought that the DVDs were over-priced, so I can't see any point in buying DVDs there, especially if you are not certain whether they wil be compatible.
Regards
Rob