of course the ubiquitous 'BME' comes to mind.....while you do need to pay for the privilege of trolling around in their 'gigantic' site, you will see quite a number of castrations and cock pierce, chop, split, abuse, and removal photos, stories, discussions etc...or...you can (like me) submit you ...

I think you will find the constant assault on your balls to be very pleasant for an extended period..... I have been pushing myself further and further for quite a while now (maybe three years) ...nothing like the feel of cold skin and the knowing, the knowing you could (maybe should) just let it go ...