I shoot IDPA competition with my glock 34 but kept my original sights, but! what I do is use Birchwood Sight Black. Make front and rear sights flat black. Look on ebay for the best deal. I bought a large can for 8.99 plus 5.99 shipping. A small can from Midway or Brownells, and amazon will cost you about 27.00!!!
Using the sight black still leaves you with an adjustable sight. Sight black works great and cleans off easy with no harm to finish. Been using it for years. You should try it.