Not to be a pr*ck like some people, but if you do a search on speakers I'll bet what all these guys are telling you will be confirmed. Other members have tried different speakers and the Hogtunes always seemed better. I use them.
If ya want to invest $750 instead of $200, you could try the Hawg-wired set-up. I don't need any more volume on T.Bagger ('03 Ultra)
Also, Pez is a member of this forum. He'll be more than glad to help you out.
And the most important factor (to me at least). Hogtunes are warrantied for 20 years.
Like Mega said you could spend $225.00 now and be done with it. You could also put polk db's in it. They will fit, but you will buying the HOGTUNES in a matter of time. You will not be happy with anyting elso. I have them and have never had a problem. In the odd case you do have a problem PEZ is the man. He will take care of you no matter what.......
I bought $18 wal mart speakers, I think they are roadmasters or something. Sound much better than stock, but I can't compare to anything else. I heard about these from another forum and I'm pretty happy. Not sure they will fit in the rear speaker pods, but they work in the front. I'd say 1/2 volume with these = full volume with stock.