I'm going to assume you're going in teams of 3-5 People. Firstly, I wouldn't bother with a Yak, even though you might get a few items, the convinience of a Unicorn is preferable. (I haven't used a Yak personally, but I've heard several accounts) I would bring around 4 Brews, 4 Super Restores, 2 Pure Extreme sets (assuming you have them), rest being Prayer Potion. Of course, remember to bring Unicorn scrolls, a teleport tablet and the basics. If you have th required herblore level, then a few Spec Restores are fun to utilise as well. Oh, when you go sara, do tell me nub, I wanna join.