bigjoe,
Since the rear bike receiver hitch has a 100lb weight limit, the lighter the cargo carrier is the more cargo you can haul on it.
Steel cargo carriers will weight the most. Usually they range from 30-40lbs. If you buy a steel cargo carrier made for ATV's then you can find them for about 25lbs. However, ATV cargo carriers are smaller and usually have an elevated cargo platform.
Aluminum is lighter than steel. Most aluminum cargo carriers are 20-30lbs.
If you want the best of both worlds (an aluminum ATV cargo carrier), the only one I am aware of is made by Guide Gear:
http://www.sportsmansguide.com/produ...d=%7bsdc_id%7d
It weights 20lbs and would give you 80lbs of cargo capacity to stay within the 100lbs spec. The cargo platform is elevated 5" so not sure if that would interfere with opening or closing the rear end of your TM.
If you don't want the elevated cargo platform, Guide Gear makes a slightly larger capacity aluminum cargo carrier :
http://www.sportsmansguide.com/produ...city?a=1728236
It weighs 15lbs and would give 85lbs of cargo capacity to stay within the 100lb spec. You are probably not going to find a cargo carrier that weighs much less than 15lbs.