You are actually asking a question, that ends up asking more questions.
HD = home defense - most people associate with inside your home defense. But you state 100yards effective range, which means you are more or less saying "homestead on 9acres or so - defense".
If you are attempting to setup a shotgun for both inside home, and homestead defense. You choices are very easy.
A. #00 buck for inside your home (for potentially less over-penetration than slugs (i.e. you only go through about 3 1/2 walls if you miss vs. slugs you go through about 6+ walls if you miss
http://www.theboxotruth.com/docs/bot3.htm). - effective to about ~10 yards smooth bore (although I can get 15 yards with certain ammo brands from mine - after lots of ammo testing on my 18.5" smooth), perhaps as far as ~20 yards with the improved choke (I haven't tried myself as my Improved Choke barrel is 28" not a HD setup).
http://www.cheaperthandirt.com/Articles.asp?a=Hunting/Choke-Tubes-Explained&Meida_id=20
B. 1oz - 2 3/4" rifled slugs for easy reach out to about 100yards.
Since you are also saying a defense scenario - you will want a fast acquisition sights, so: Pick one.
1. Ghost rings
http://www.xssights.com/store/pix/catalog/shotgun/shotgun1.jpg
2. Fiber optics (front & rear example:
http://www.securityandsafetysupply.com/media/night_vision_images/truglo_n_2.JPG
3. holographic
http://www.anchortex.com/graphics/eotech/550.jpg
Myself I generally keep my sidesaddle on the shotgun loaded with mostly #00 buck. Then I keep an ammo pouch with slugs near the gun. As fate would have it, the best #00 buck for my gun happens to also be in a RED plastic shell, vs. the slugs I like are in a CLEAR plastic shell, so it's easy to determine which slugs I'm loading as well.
Have fun.
-M3