(imac) using external ssd drive to work on recent photos anyone?

[snow patrol]

Hi all, the way I do my processing is to load all my images onto my NAS unit and work on them from there. However, it's not exactly super speedy, and so i'm considering getting an external ssd solution and using that for the weddings i may currently be working for, before re-backing up on the NAS.

Would this work well? Is it a good move? My imac has thunderbolt and firewire.

Thanks