Replying to Starting on a fish

I've been surfing a few times and have been getting into it a lot lately.  I'm not ready to buy a board yet and will keep using the rented board that i have been using for a while, but i feel like i am progressing really fast.  I want to buy my own board within the next few weeks and after doing some research i feel like a fish might be a good option.  I know some people are dead set on a longboard or mini-mal, but I would like something with a little better turning ability.  That's where the fish comes in.  I know they are much wider and thicker than your average shortboard so i feel like they would yeild the boyancy i probably need, but also the manueverabilty i will desire in the future. They will also do well in the mush from what i have read, which is something i will need in certainn parts of the year. Also, for reference, I'm not a small guy - 6'1" and 200 lbs (not fat at all, just a strong, solid build).  For all you experts out there, is this a reasonable assumption or will getting a fish make learning too hard and frustrating?  And if its ok, what lenght fish would you reccomend?