Advice for a gallery plugin

Dear all,
I’m new to WordPress world so I’m sorry if this post might be a bit silly.

I’m using WP to create my own website and would like to add some picture galleries.

I’ve tried the Gallery plugin, but the problem is that when I upload
a few “HQ” (7-8MB) pictures the browser freezes.
Also even if it wouldn’t I’d rather not create a gallery using pictures of 8MB each.

The plugin I’m looking for, ideally makes this:
when I upload a picture I’d like that a thumbnail and a low quality 80% compression jpeg to be created (1024×800 px).
When one see the gallery as a slideshow, the light jpeg version should be used rather than the original picture.
However I still would like the original picture to be uploaded on the
host, so that should I need it for printing I have a backup of it.

Is there any plugins that allows me to do this?
Thanks a lot for your replies,
Cheers, Luca