Adjustable sights

I have around 1000 rounds through my Stainless Target and the rear blade of the adjustable sight will not stay tight, It almost fell apart at the range this week. My question is does anyone make a fixed sight that would fill in the void of the machining in the top of the slide? Sounds stupid, but questioning the need for adjustable sights. If no fixed sight is available, should I send my slide in and have Kimber put a new one on or should I fork out $60 to have Bomar's put on? Am I better of spending $60 on proven Bomar's or $?? in shipping, only to have my next Kimber sight fall apart at 1000 rounds? Sorry for being long winded, but I am getting a little frustrated with the sights, and even more disappointed in my decision to by the target instead of the custom. Gun works great.

Mark