Question: does the size of the hard drive upgrade matter?

I'm planning on upgrading my hard drive for my ps4, and I've looked over everything in the sidebar and I understand what to do.

I'm going to purchase the

"Seagate Backup Plus Portable External Hard Drive with 200GB of Cloud Storage USB 3.0"

And was planning on getting the 4GB one. Will there be any problems with the size being 4GB over a 2GB? I just wanted to make sure before I purchased it. Any input is extremely appreciated!