Jump bike ss bottom bracket
 

Hi i've converted my bike to single speed, and recently started hearing clicking/knocking sounds coming from my bottom bracket, i took off my cranks and moved the axel of my bottom bracket. It was moving up and down by about 2mm! I obviously need a new bottom bracket, but what shall i get.
Requirements-
Square taper
Hard wearing (for jump bike and single speed)
Affordable

Product names and numbers would be much appreciated!!
thanks
dan