Long term, two copies of Keyclone, one per machine.
Ends up costing you $20 each, or $40 total.
And that is good forever.

I personally think IS Boxer offers more features, making it a stronger choice for boxing.
But the cost is $36 per year (subscription is good for up to 5 computers).
In the first year it's about the same price.
But then you'd need to renew.
The additional options are worth it, in my opinion.