Give or take, it's been three years since I've posted here.  The short-short version:

- Back injury. Not related to the bike, but I couldn't have kept riding even if the stock seat didn't hurt to sit on.
- Back surgery.  Fixed 2 discs in my lower back.  Took some time to recuperate.  
- Baby.  She's a delight.
- Blew up the bike.  That's a bit of an exaggeration, of course; it overheated, blew out the oil cap, and the sprayed oil caught fire.  No other damage, but after that I was afraid what the damage would be so didn't take it in.  I wish I had taken it in sooner... A carb cleaning and oil change later (and a replaced oil cap) it runs better than it did brand new and I'd like to start riding again.  

But that brings me back to that horrible stock seat.  I'm 6'0 and so it was bad before my back injury.  It's the #1 thing I want to do something about it before I begin riding again (#2 being learning how to do elementary repairs to the bike).

I've done a little research:

Corbin appears to make a really nice seat just for the S40.  Despite the price this appears to be the most attractive option... if it's going to be kind to my back and tailbone.  Anyone tall use one of these?

This guy did a simple, cheap, yet ugly mod that addresses the problem but appears to raise your center of gravity half a foot or more.

Then there's this guy who suggests that Harley Sportster seats fit the S40 with minimal modification and suggests that this is a good place to ask about how to go about doing it.  

Or does anyone have a better suggestion?

Welcome back. Glad to hear your looking at riding again. Might want to think about the cruiser riding position as being part of the problem. Yes, the stock Savage seat bothers a lot of people, but probably a lot more ride without any modification. I think some people just have better spines.

The cruiser position basically just bounces you up and down at best and at worst crunches your tailbone without letting you used your whole body suspension (legs, arms, and spine) to absorb the shock, so the MC provides all of the suspension (and lets face it, small cruiser suspensions pretty much suck).

Let's see... I'm 6'2" 240ish...absolutely destroyed lumbar spine...

High bars, cut down HARD seat (3/4" ensolite padding), Intruder shocks. Works great.

Squishy seats aggravate spine issues.

Degenerative disc and joint disease is why my 57 Panhead rigid with a springer is patio art. And why my speedster/tracker barred Honda is patio art (for the moment, need a canyon carver).

Unless you had a fusion you will end up with ongoing issues. My first surgery the "repairs" lasted less than a year. The second surgery the results ended up the same, just took longer to be re-agravated.

I can't ride a stock seat anything anymore. Swap it out for a thin sprung solo or a hard mounted thin seat and I'm fine. As long as my butt stays higher than my knees I can drive alright. My bench seat pickup? No problems. My wife's 95 Outback? I carry a ball head cane with me...

You get used to it.

Ive noticed that when the bag is loaded & kinda intruding into my space a bit, I use it as a backrest & it`really changes the comfort level. You might try trapping something on the seat, right where you need some low back support.