Grunker
You mentioned that you were going to be respeccing your companions, any idea as to which of them you particularly want to bring with you and the kind of party role composition you're likely to go for?
Not at all. I know I want a shield basher for a fact, but that should pretty much build itself, no? So many necessary feats.
I'm also strongly considering a Witch. I'm actually not too fond of the class on paper, but it's one of the Pathfinder classes I've played very little with, so it seems like a no brainer.
Then I wanted to do a staff monk, but since I found full shield bashing was in I've gone back a little on that since it could end up feeling similar to the shield basher, which is definetely going in.
Student of War seems fun, lots of stuff you could do with that, so that's definetely on the table as well. Could be rolled into the shield basher as well.
My main goal is having a party with (a) fun/off-kilter builds that (b) are strong enough to handle the hardest difficulty but (c) don't abuse exploits or otherwise make fights too steamrolley. This was basically impossible to achieve in Kingmaker since any competent build inevitably scaled out of control - even my shitty homemade ones - but I have a bit more faith I can come closer to that ambition in Wrath.
Ember (CG, Elf) is a Stigmatized Witch and is pretty solid with her build so you could just take her as is. She also has a personality that you'll either like or loathe. She has some funny interactions with Daeran (NE, Aasimar, Oracle), so taking those two along could be entertaining. I quite like both of them but I can see why others wouldn't.
Wendaug (NE, Mongrel) starts off as a fighter with 16 STR and 20 DEX who could easily be turned into a shield basher, though she lacks intelligence so you might want to respec her if you want to make her a student of war. She's another one you'll either really enjoy having around, or want to kick her out ASAP.
Camella (??, 1/2 Elf) she is helpful.
Lann (LN, Mongrel) tends to shift between wisecracking and sulking. I don't like him much if I'm honest, but his starting attributes make him good to have around if you didn't respec. As it is I'd probably choose Wendaug instead, she's more interesting.
Woljif (CN, Tiefling) has the sort of personality that you'd expect a CN thief to have. Archetypal.
A lot of people seem to dislike Seelah (LG, Human, Paladin) because of her voice actor. I don't hate her personally, but she's also not that interesting. Paladin who started out life as a pickpocket and struggles a bit with her current career choice.
Regil (LE, Gnome, Armiger/Hellknight) is great to have around. Probably one of the better-written companions.
Nenio is an annoying Neutral kitsune mage who is generally annoying except for the times she's busy being annoying.
Soseil is a NG Human Cleric who is always painting when you see him in camp. Has a horrible build with junk feats and could really do with a respec. Has quite an interesting questline that could unlock a hidden companion.
Greybor is a Dwarf Slayer hitman. Owlcat say he's neutral in alignment, but should probably be lawful evil considering his personality and job. Could also do the shield bash role very well.
Arueshalae is a CN Succubus trying to make herself ascend. You can help her do so or turn her back into a demoness.
As for builds, I'd recommend taking a full divine caster, a full arcane caster (could be the Witch), a skald or a bard, at least two front-line fighters, one of which should be mounted (could be the shield-basher, Gendarme Cavalier would fit well with feat requirements for that), and at least one ranged specialist who can do serious damage (I currently like a crossbow-shooting rogue/slayer type best for this job, but a Ranger also works well).