Move site from wordpress.com to selfhosted site – how will images be displayed?

Hi everybody,
The last week I have been reading a lot about moving a website from wordpress.com to a selfhosted site with the wordpress.org software.
I have lots of images that are displayed in the wordpress.com gallery.
If I import the images in my new wp site, how will they be displayed? I would love to have them displayed in a lightbox. For instance the one from Nextgen. Is that possible?
Or is it beter to only export and import the rest and create new galleries with Nextgen?
That will be a lot of work though.
Just curious what the best way is to do this.

Johanna