Been looking for a good seat for my 2013 Softail Standard, one that pushes me back and down a bit due to being 6’3. Most seats available for the FXST don’t seem to accomodate tall riders, for example the Le Pera Daddy Long Legs or HD Tall Boy. Standard plank and Sundowner push me forward leaving me really uncomfortable after a 100ks or so which seems to be the case with many seats on the market.

Besides having the best avatar here, that is a bloody good question to put forward to Baldrick.. Your not looking single seat, I guess the bike you ride also dictate position/s and having to work around such. Myself am only 6 foot, but with my motorcycle which is a Road Glide I find am stretching for stuff, although I spent a squillion dollars on a Danny Grey seat, that is not that pretty, but function is on the nail,. Can ride 1000kms and not have a fucked up arse... Times have changed. Ya do not have to endure arse fucked from long rides. the stories I bet a lotta blokes could tell, on the speakeasy here, riding from Home to Bum fuck then another Bum fuck, and loving  it mind you, but younger than now, and would be pushing  a "little" to do again.

I have a Danny grey speed cradle on my softail rocker the seat it sits you low on the bike, have not been for a long hall yet but around town Im pretty happy and very happy with  the look, if you buy from Danny grey USA its $150.00 extra fucked if I know why but thats the story 

If I got smashed every time I posted / typed something incorrect I'd have to change my name ..... chin up straight were all Bros here mate.

Baloffski is a good fella. They're just words, just dunno where they came from.

Gee Sean. I had not see nor heard you for a long time. Thought you must have given up bikes. You can go 2 or 3 inch extended forward controls. Like Burra had to.. this with tall boy seat should do it.

Yes Blackadder, I found the standard seat seemed to push you forward and got myself one of these. It's a Le Pera, king cobra. It works much better for me. It is lower than the original one, and has less thickness behind your bum giving you more leg room, plus I kind of like the fluid lines of the thing visually. It may not look like a good seat for a pillion however the few times my missus has been on the back (got her own bike) she preferred it to the original one as well. They are also available with a "biker gel" inside. Which may be more comfortable on longer rides.
If this one does not fix the problem maybe you need the forward controls extended.

I'm a bit shorter than you at 6'1.
With regards to them being uncomfortable, all I can say is that for the bike, I find this seat WAY more comfortable than the original one.
Also, after a fair while in the saddle if you want to stretch your legs a bit you can sort of push backwards with your feet and put your arse up on the pillion seat for a bit. You might look a bit silly but it gives a bit of temporary relief.
I can quite happily ride through a tank of fuel (300+ klm) , fill up and go again without any issues.
Guess if I had my time over again I should have ordered one with the gel interior and red stitching to match the bike.
Comparison pics for your perusal...

I use a Lepera Bare Bones seat on my FXST with forwards and apes and im 6'4 and can ride that fucker all day. 

Sean, Have you thought about getting your seat made to suite yourself,  There is a Good bloke  at Goulburn and another out near Bathurst. ( heard good things about both)

This way can get the drop down part at your lower back shaped for you.

Just looked up HD Catologue,, Genuine Tallboy seat for 2013 FXST, Part # 51469-06A,     Puts rider back 2 inches & raises 3 inches compared to standard seat.

LEPERA BARE BONES