You usually don't want to be grappling if you expect someone to go 'splodey on what you're grappling. They have a harder time aiming because you're in a grapple with something. You might be able to get Improved Grab to work around that, but I can't be certain. If you really want to grapple,
SirPercival's grappling handbook might be worth a read.
If you go for tripping, make sure you can take the
Knock-down feat. That way you don't typically have to spend an attack on tripping, but tripping on its own might work better since it's a touch attack instead of against the target's full AC.
One of the common things done by optimizers is Lion Spirit Totem (Complete Champion) and Wolf Totem barbarian. They have some slightly at-odds fluff, but they can be taken together since they replace different barbarian abilities. Lion Spriti Totem allows you to make a full attack at the end of a charge in exchange for the barb's Fast Movement. However, you might find the increased base speed from a non-lion barb to work better for you given your dwarf character.
You could go with a spiked chain for reach, but dwarves have the opportunity to trade their weapon familiarity (see rules in Complete Warrior 154-155) from the dwarven axe or dwarven urgrosh to the dwarven warpike (Races of Stone 155). It's a reach weapon useful against charges and it can make trip attacks, but it doesn't allow attacking close stuff like a spiked chain does. If you went with armor spikes you could still threaten your normal range while two-handing a reach weapon like the pike. You won't get TWF penalties either.