Congrats! jay628..... Man, you didn't waste any time : ) welcome to the DN1000 club! As far as spacers go... Red spacers have the least bass and the most pronounced treble. No spacers have more bass and less pronounced treble. Longer the spacer, the lighter the bass and the more pronounced the treble is. These changes aren't night and day. I recommend you pick the setup that gives you the best fit.
Tips..... Wider bore = wider soundstage and fuller mids. Narrow bore accentuates the bass and treble and recesses the mids. I prefer the wide bore grey reinforced silicone tips. They will improve slightly with burn in, but it's subtle.
Glad you pulled the trigger. Enjoy, my friend!