IMO, good quality is more important than capacity. Bear in mind that all the pulling effort comes from the work that the operator is doing, so it doesn't matter how much of the mechanical advantage comes from the length of the lever, versus the Come-along mechanism, versus snatch-blocks.
The advantages of buying a smaller come-along and extra rigging are numerous:
- More manageable
- Lighter and easier to pack
- More versatile (only use the extra rigging when needed, rig in different ways, etc.)
- Probaby cheaper, and rigging will out-last the come-along.
The other thing to watch for is what the ratings mean. Often the "2-ton" (or whatever) rating is some meaningless "horizontal pull rating", where they assume you are using it to pull some sort of rolling load (instead of being the ultimate amount of tension the device can exert on the line). It will also already factor in a snatch-block, if one is included.