It sounds like the larger pulley/belt combination would give you more low end power. The down side is that you lose top speed.
The rear sprocket option Chris offered would do the same thing but is probably harder to change and you would have to buy a longer chain.
Essentially, either of these changes just gives you a lower gear which you are then in permanently. This means better take off, more hill climbing power and lower top speed.
The "less throttle and pedal" option form Jim, is also good, especially if there are not too many hills.
If none of these are acceptable, you would have to look at a Biturbo and larger carb. This would allow you to lower the gearing without losing top speed. Others who have done this will probably post on the subject.