I'm assuming you meant WPA Radius and WPA Pre-shared Key.
WPA Radius would require you to install and configure a RADIUS server, but would give you more authentication and authorization capabilities.
WPA Pre-shared Key should be fine for your setup. Basically, they'll have a key and if it matches, they're allowed onto the network. There is no additional rules that could come into play as to what they can access like you might have with a RADIUS setup, unless it comes from group policies as part of a domain that they are logging into.
The decision is up to you...but there is nothing wrong with WPA Pre-shared key, it just does not provide the more advanced capabilities that a RADIUS setup might offer. Are you using AES or TKIP encryption?