+2 on http://www.easternperformance.com/ .
There website is terrible for looking up anything for a Dyna.
Seems everything on there is Softail oriented.
You'll find a good selection of parts if you go to their Ebay store.
Tons of Dyna specific stuff to be found there.

 

http://www.mandmcycles.com/
aftermarket and oem
good discounts and great people to deal with
check it out

 

m&mcycles are good
phatperformance also
axiomcycles is a good bet

my choice is like a lot of others
eastern performance

if looking for a specific item, call any of them and ask if they can get it and price. or use their email.
just shopping around is all it is.

for fuel managers - Fuel Moto

i've bought from all the above.