For the Witch, you'll want Accursed Hex feat, and Ability Focus (Slumber) if the Bestiary is allowed (if not....how do polymorph and summoning spells work?).
At lower levels, until it becomes too weak to survive blast effects, riding a mount is actually really handy for a witch who plans to cackle, so you can actually move around the battlefield yet also cackle + hex or double cackle on a given round (note that, because of the wonky way misfortune and the like are worded, if you do not have a move action available to cackle IMMEDIATELY after using it, the "1 round duration" will cause it to expire before you get a chance to cackle on your next turn; I think it's dumb, but you can at least double cackle for +2 rounds duration on non-busy rounds, so....eh). Just need to make a DC 5 ride check to guide it with your knees.
For other party members... you basically want as many casters as possible. Shocking, I know, but PF is kind of caster paradise. A druid, despite the nerfs, is still a solid class, as is cleric. Druid before Wildshape still has scythe and scimitar proficiency, so give him a decent str score and he can handle himself just fine. Cleric... I don't play them much and am not the best source for optimization advice.... Any deity that gives a good weapon or has travel domain is a pretty safe bet, though. APG means you have access to the delicious Teleportation and Foresight subschools, I prefer Teleportation because it gives you a Su teleport to escape grapples with and it means you can prohibit divination (a lot of div. spells are off-day things anyway, so spending 2x slots isn't as bad, and the party witch gets most of them anyway).
So, I suggest for your party: Druid, Cleric, Teleportation Wizard with Divination and...let's say Abjuration (other casters can pick up the slack on it) prohibited, and Witch. The first two can tank just fine, and all 4 are capable of summoning in extra meat shields.
If you absolutely insist on having a "non-caster" in the party.... APG means weapon and shield style ranger is open. I have a build that goes Ranger 6, then into Fighter, and 2-weapon fights with (at level 6+) spiked bashing heavy shields. Ranger lets you get Shield Slam (freee bull rush every hit!) at 2 and Shield Master (no TWF penalties at all! shield AC enhancement applies as a weapon enhancement too!) at 6, both early entry.
Actually... APG means Horizon Walker is available, albeit the heftiest source of abuse is not. Still, you can totally enter it, min-max your favored terrain bonus, pick a favored enemy that is only from that terrain, and then use a wand of Instant Enemy to treat the target as your favored enemy for "all purposes" (ie, including what environment they're from). And thus apply your MASSIVE favored terrain bonus as a favored enemy bonus for stupid crazy attack and damage. Certainly not a low level build, but definitely the cream of the crop as far as high level martial builds go in PF.
