I say think about what you will use your water for. Will you use it for questing, pking, events??

Have a look too at the JS of both a wit and seer. Which one will help you more?
Do you want a Wit's JS- Cuss (adds 50% target damage)
Or do you want a Seer's JS- Foretell (Frees one person from any seal)

Most people don't find a Seer's JS too useful, especially since it only works on one target at a time.
Wit JS is very useful but you may already have a wit and may like variety.

All up to you in the end. Good luck ^.^