If you want a high-power hard-cranking battery for your hawk, and want to put it in the same place, consider the YT12A-BS
YTX9-BSYT12A-BS
Use:Stock/OEMHigh-power
Battery Family: Maintenance Free
Voltage: 12
Capacity: 89.5
Dimensions: 6" x 3.4375" x 4.1875"
Metric Dimensions: 150mm x 87mm x 105mm
Weight: 5.4 lbs. / 2.5 kg6.3 lbs. / 2.8 kg
Acid Volume: 0.40.5
Amps: 0.91
C.C.A.: 120175
expect to pay:$65$90

These two places that have these batteries, based on a quick Google search on November 20, 2003. This is not an endorsement of any sort, I know nothing about them, but their prices seem decent.

BatteryWeb
iMotorcycle Store
Batterycountery.com
MotoBatteries.com
Westco Battery

This place is a chain, but might have a good price:
Batteries Plus

They have stupid names, but that's because all the good names were taken before the 1980's. I expect a Google search of some combination of

       yuasa, yt12a-bs, ytx9-bs, price, battery

would reveal who has the best prices when you're reading this. in fact, try it now:

Google
Batteries can show up on eBay too: