Road bike turned tri specific

I have only ridden a road bike two times.  The first in a sprint tri I did and the second today.  My goal is to do Augusta 70.3 in Sept. 09.  I am a mountain biker and a hockey player so I have pretty good leg strength.  My scenario is this:  The road bike I am using is an old Trek 5200, all carbon, all Durarace componants.  I have been told not to bother changing anything except the geometry and the addition of aerobars.  I was fitted by my local lbs who are great people and very knowledgable.  They changed my seatpost the get me more vertical and also adjusted my seat forward.  (I don't know the measurements they were looking for, but they had some kind of weight they held to my knee and let it hang down).  They also adjusted the height of the seat to fit me properly.  After riding the bike as it was during my sprint, I could not believe the difference in my quads with everything more forward.  Is there anything else I should do besides just ride?  They suggested a different saddle down the road.  My first ride today was just under 20 miles.  I could have gone further but wanted to make sure I could make the back part of an out and back ride.  Also, I got down in the aerobars and felt pretty comfortable in a very stiff headwind.  I averaged around 21 mph.  Any other bike adjustments or aerobar suggestions?  I really want to break 6 hours in Augusta.  I've already got the swim down.  2100m in 50 min. in the pool.