I hear ya on the handling of the Phazer, I've got one and it's a fun sled to ride! Very nimble!
I think most guys will steer you away from turbo or super on a Phazer as they are not know as a good platform for these mods and generally not cost effective.
Having said that if you insist....I would lean towards super as your back east and likely trail riding with little elevation change in a day. They have great throttle response, which is nice on the twisties. With little elevation change you will not have to adjust the GEMS much, if at all, once it's set up.
I cannot comment on the Phazer but the install on my Apex was fairly straight forward.
Another thing to consider is a stock Phazer needs to run 91 octane. If you boost your going to need a head shim ($$ if your paying someone to install) or av/race gas (higher operating cost).