The LE is a fine board but I don't know if you'll get quite that much of an overclock out of it. In that price range I would recommend the ASRock Z68 Extreme3 (not the Pro3) or the Gigabyte Z68XP-UD3. The MSI Z68A-GD55 also gets good overclocking numbers sometimes.
Tom's did a review of some of the budget Z68 boards and here's the overlocking results. Unfortunately neither the P8Z68-V LE nor the Extreme3 were included, but it's some data nonetheless.http://www.tomshardware.com/reviews/z68xp-ud3-dz68db,2980-17.html
Now keep in mind that it's possible you won't be able to get to 4.6ghz regardless of the board you pick. It's the luck of the draw whether your 2500K is a good overlocker or not.