For Challenge # 020. Bone Saw and Shuko show us that +1/+0 costs total to cast+equip, so adding a minor enough ability should take it up to total. Most keyword abilities aren't minor enough; for example, first strike I think would need to cost more than total if the equipment gives +1/+0, and first strike would look pretty odd with +0/+1. But I think reach will do.
For Challenge # 020. Bone Saw and Shuko show us that +1/+0 costs
total to cast+equip, so adding a minor enough ability should take it up to 
total. Most keyword abilities aren't minor enough; for example, first strike I think would need to cost more than 
total if the equipment gives +1/+0, and first strike would look pretty odd with +0/+1. But I think reach will do.
(Sylvok Lifestaff follows a similar approach.)
Seems like a very good example to me.