Hello there Hmaddox,
I came up with a design you might be interested in.  My seatpack measures, 7" high on the seatpost, 25" on top (front to back), 28" on the bottom (front to back), and a 9" opening.  It will collapse to around 8".  When it is full it measures approximately: the front @  7" x 6",  the middle @ 8" diameter, the Back end @ 10" diameter.  Total length when full is around 24".  It's a one piece main bag which offers a waterproof environment, so you don't need to use an addition waterproof stuff sack.  It has a protection cover at the front of the bag for the heavy abrasion areas and strapping areas. 
I have found that having you sleeping kit up front works really well as long as you keep it all no more than 5lbs. After 5lbs my bike gets to hard to control on the front end.  This includes you sleeping bag, pad, and one man bivy.  I also found that I can compress the whole sleeping kit by rolling it all up together really tight which allows you to have a stable pack system.  I have found to that the more stable everything is the more consistent control you have.
I hope this answers some of your questions and helps you out. 
You can check out my Bikepacking Picture gallery @  http://lonemountaininnovations.com/bikepackinggallery/
Take a look around my site and you can view a few of my bag products close up.  I'm not trying to sell you anything but enjoy being on this site to share the journey in all this and learning from each other.
Keep innovating!
 

As a noob to both this site and bikepacking in general, I really appreciate your dimensions and willingness to help out.  I'll be doing some DIY seat packs thanks to this post.

Syb

if it wasn't for these posts, I wouldn't have a clue. 

Agreed.

To outfit your new ride will you be doing DIY projects, having the forum vendors make them, or going with big bike outfitters?
This site has a lot of guys with design and thread injector talent for making custom bags and offer their work for a very fair price.
Two I used was Jandd and Jpaks there are many others.

I've found a ton of great info and advice here on bikepacking just look at  Eastman's or jbphilly rigs in this thread
tells you these guys have been doing this awhile and know what works.

This site is a little different than the one we frequent in that you will see 1000+ views on a particular thread but only a hand full of
guys posting their thoughts or ideas. I'm not sure why that is. I'm hoping threads like this one on short bikepacking trips not necessarily epic rides
will get the group riding, taking picts, and posting.

The initial plan is to start out with some DIY.  Frame bag and seat pack specifically.  I've got plans already and this weekend will be roughing some of them out. 
I did see Jeremy's (jeremy11 here) work here and might go with his packs if I screw up too badly. He's got the right attitude and rocks a beard like nobody's bidness.
I recognize jbphilly's nick from HF and he's got a great setup.  Great things to aspire to.  (I love grammar)
There is some great info here and I'm on overload with it all.  The differences are strange but even more so than hammocking, this just might be an even smaller niche. 

Hi Jeff,
Small world, I saw the pict you posted of the new bike in the HF forum.
That thing is going to be fast. Your going to have to find longer ways home
just so you can peddle a little longer.
aka OutandBack

Hey Bob!  I would notice your outstanding pics anywhere. 
Yes, the bike might be fast but it's the engine that keeps slowing it down
I've already got plans for a frame bag and seat pack for the new ride.  I plotted out two paths I can take on my way home to do some practice setups.  It might make my commute home a little longer but all the better.  I've got a good chunk of $$ paid toward it and my LBS is holding it on layaway for me.  Pics when I get the bike. I promise.

All these pics are making me jealous!  I can't get my new bike soon enough!