As far as open sites go...the Williams rear site proposed by 'Rear Peep' is very good one. It is definitely what I would use for target shooting. Some folks might prefer a more-streamlined version that doesn't hang off the side of the barrel, which could end up snagging on your sweater or something else out in the field. There is one, and it is also made by Williams. It is the Williams WGRS-Legend Guide Receiver Peep Sight. Check it out at Midway USA for about $35.
If you aren't concerned with snagging the sites on something, then you might also consider a front site other than the fiber optics from the factory. Here's one option - it's a combination of the Marble Arms - Dovetail Front Ramp ($12) and Lyman Target Front Sight Model 17 AHB .404" Height ($40), both from Brownells. I believe the Lyman globe site came with a card with a variety of inserts. If it doesn't come with something you can use, you can order one from Brownells. Have a look at the Lee Shaver Post & Aperture Card, 17A Sight. The aperture inserts are pricey at $22, though.
It should be noted that the Marble Arms dovetail only matched up to mount with one screw instead of two, and that I had to locktite the Lyman dovetail into the Marble Arms dovetail to get it to center and stay put. That sounds pretty shaky, I'll admit, but it has worked out well so far - I can get very nice groups with this combination at 200 yds. I suppose you could have a gunsmith drill and tap a hole for a second screw on the front. If someone else found a better dovetail for the front, I'd be interested in knowing.