Hey Dan,
For getting to 25 points you might consider a unit of infantry like Kriel Warriors, which are cheap in points, but are a worthwhile monetary investment. The Kriel Stone Bearers are also a staple in most Troll lists that I see, and will buff your beasts and warrior models.
If you're wanting to go the beast route, you'll want something that can deal with infantry, so the Bomber would be a good choice.