SSD/HDD: Which one for me?

hey guys i'm trying to decide on what i should do with this Mac Mini mid 2011 that has the 500GB hard drive it came with. i was thinking of buying a 128GB SSD and an external USB drive to store my data. or should i just buy a 500GB hybrid drive? how else can i make use of the peripheral ports at the back of the Mac Mini?

what can people recommend i do for my situation?

thanks!