Nitrorulz:
Here are some places to get that Pinion Gear from.
I would first try here:
http://www.fg-hopups.com/photo_album.html
Item 7010. $35 bucks plus $5 shipping. He didn't have them in stock when I tried to order from him and from what I hear he isn't really selling anything any longer. He's bad about returning e-mails but after I purchased it, he let me know he didn't have it in a few hours.
As for HobbyThek in Germany, they are great to order from. They are very quick (received mine within a week!). There is a currency conversion calculator there so don't be intimidated by that place. They also answer e-mails to questions very quickly.
For steel pinions (19 tooth):
HobbyThek in Germany. (shipping is outrageously high, but they get it to you in a week)
Pinion
The Firehammer MT came with a small alloy engine mount already, so I ordered the large alloy engine mount from HobbyThek.
Large Alloy Engine Mount
I would also eventually suggest FG Part #08484 Alloy Diff Housing (order this from LargeScaleRC.com or rcnutshobbies.com). If you have the money, get it sometime. You won't have to worry about stripping your gears out!
Other cool stuff from HobbyThek for the Firehammer and FHMT:
Hopups
Also,
www.tqrcracing.com sells parts for their HobbyPro clone. I swear this place has parts dirt cheap. Doesn't look like they have all the Firehammer MT parts like arms, but I purchased 2 pair of steering knuckles at $2.40 a pair for backups!
Also, check out
www.hobbypeople.net. They used to sell the XTM Grizzly which is another clone (exactly the same as the FHMT). Just do a search for Grizzly. I use them as a last resort for parts but you'll usually pay twice as much for the part. Tower has been awful about stocking parts for the Firehammer. Parts are much higher, but you get them faster than you can from TQRCRacing.com (so far, slow service). I just ordered some stuff from TQ last Thursday, still haven't received shipping confirmation yet they have my money! Ordered from HobbyPeople on Friday (the steering knuckles) and had them in my hand on Monday evening.