1318 and 1469 are both great yeasts for bitters - they are my go-to yeasts in that department. I have not used them in a porter though, so, can't really add much in that area.
When I use 1469 I try to keep fermentation temps in the mid 60's.... I find that if you get 70+ you can really get some strong flavors that can be a bit much.
If I was going to pick one of those two, I think I would lean toward 1318 over 1469.... but, maybe others have more experience using 1469 in porters.
Kegged/Serving: Porter, Session IPA, Dark Mild, Ordinary Bitter, Double Citra IPA, Oatmeal Amber Ale, Bo-Pils,
Bottled: Barley Wine, Sour Belgian Golden on Cherries, Sour Cherry Stout
Primary: Alt, Scottish 70, Dortmunder, Bo-Pils
Future Brews: Heady Topper Clone, Helles, Porter, Plain ol American Ale More...... More....... Beer.......