Make sure the years of the bikes will work. 07 and up are different mounting. The OP's is pre 07.

But I'll vouch for the Firehouse customs. Very comfy and look good. (I wish I had a picture to post). 10 minute install on the 07 - up version.
Spring loaded and fit the back nicely.

 

The seat for the springer I have is from 98 and fit my 07 luxe with out an issue so I don't see how it would not fit nothing on the seat was changed and was a direct fit. That being said the mounting holes are the same on both seats so it should mount up just the same. Just my opinion from what I have

 

Cool. I seem to remember my 04 Heritage seat mounting different than my 08. Maybe 08 is when they made the change?

My 08 has one screw behind the rear cushion, that pops the rear portion off. Once that part of the seat is off, it exposes two thumb screws that hold the front seat on. The backrest mounts to the same two thumbscrews. If the bike wasn't buried, I'd have taken some pics.

Is yours like that?

 

Yeah exactly honestly I realy don't know unless they switched things up inbetween the reason I am saying this is that if a springer seat from 98 will fit my 07 then the opposite is true and this thusly opens up the door to many more options that may not directly be made for the model fore it works out great I have two seats and one backrest and use one for town the other for long trips so as far as I can assume as long as the mounting is the same on the heritage springer and heritage classic then the options are almost endless. Then again I could be wrong

 

I had a Firehouse on my Deluxe and one of these: http://www.utpr.com/ on my FLHTC - can't go wrong either way. The Utopia has a built-in pocket, which is pretty handy; and it's a little heavier built than the Firehouse.

Firehouse customer service was great, Utopia customer service was extraordinary.

 

This guy put a custom backrest on my Road King. It has a metal tab that slides into a slot in the pillion seat. Pops right off when it isn't needed.
http://www.richscustomseats.com/

Rode to Sturgis without a windshield. It worked great in supporting me against the wind.