definitely, a friend of mine had an 07 wagon and did all LED tails which were awesome! and i have seen a few amazing looking headlight sets for those (my favorite having 3 little black diagonal stripes on the outer part near the turn signals) they have some really cool set ups for those years.
by puddle lights do you mean those little spot lights on the side that shoot to the ground? if so then YESSSSSS! that would be sick, freakin classy legacy wagon limo status! love it.
you should do some little vinyl overlay tint over your mirror turn signals, ive seen 1 or 2 with it and they look really good, as long as you do it right... ha ha