NAPA or Autozone will probably have what you need. Try looking it up on their site beforehand. Then you'll have part numbers when you go. I've been able to find pretty much any obscure bolt that I've ever needed at NAPA.
And of course the dealership will have them. I'd check other places first though, the dealership will probably be a ripoff.
Also, you could try checking out hondaautomotiveparts.com. I'm sure you could get the bolts you need there, and probably for cheaper than through a dealer.