A 40/40 set is a wand and an offhand set that each have 20% chance halves skill recharge and 20% halves casting time of spells. It does not actually work out to be 40% on both but everybody just calls it a 40/40 set
Just fwiw in the interest of helping, you can also find helpful info like that in the sticky here in the Questions & Answers section about common terms.
There are some collector weapons (mostly focuses) that are 20/20. You could get them very cheep. The wand will run about 5k or more depending on what you want to get.
I think 40/40 is just what you need to improve efficiency. But Quaker is right, don't need it entirely. But its definately a must to have if you plan on pvping.