Spice additions to Brickwarmer Holiday Ale (1 gallon)

I just ordered the one gallon kit for the Brickwarmer holiday ale and was thinking about adding in some spices (cinnamon, nutmeg, ginger maybe…the kit comes with orange peel already). My question is, how much for a 1 gallon batch and when is the best time to add them? At the end of the boil? Directly into the fermentor? (Since this is a 1 gal kit, there will only be primary, no secondary). Will the spices dissolve at all, or will any leftover sediment settle to the bottome during fermentation? Anyone else tried this? And, if so, how did it turn out? If it sucked, let me know now and I’ll just leave the recipe as is! Thanks!!!

Brew it as is, then soak the spice candidates in vodka for a couple of days and add to taste at the end of fermentation.