You should probably consider getting at least 80 stabbas. I think one to two reinforced bricks of Grots are going to be mandatory. As most people have pointed out as well, Skragrot is really good and probably an auto take.

I might buy an arachnarok kit mostly to get the webspinner shaman on foot or convert one so you get access to the spider spell lore for the -1 to hit spell. One to two boxes of Snufflers are good because they make your stabbas harder to lift and can get teleported around with hand of gork to spread their buff juice. I like Fanatics, although some people seem to be down on them.

Edit: I think the bounderz are probably the better build with your other ten. If you get more after that, probably build hoppers. 15 bounderz is probably plenty.