Here's what you want to get...

http://www.midwayusa.com/viewproduct...tnumber=968159



Williams FP-336 Receiver Sight. Comes with a small aperture for target shooting and daylight use, and you can either buy larger apertures for low-light or just remove the peep and use the 3/8" opening the peep screws into as a ghost ring. Williams also sells replacement fiber optic front sights, but the existing front site will work fine. This sight screws right into the existing rear scope mount holes, so it's an easy DIY installation. The "FP" version also has micrometer windage and elevation click adjustments for ease of use, and the adjustments have set screws to prevent accidental changed to the zero once set.

Oh, and at $60 it's quite a lot cheaper than the cheapest decent scope you can get.

Mike