Ka Bar, what is more useful, the D2 or the Next Generation in 440A?

I've been wanting a Ka Bar for a while now and its getting close to Christmas. I've been wondering which metal would be more practical for heavy duty work and that will refine its edge more longer. I also want to know what sharpeners to use for D2 or next generation since the metal is stronger then 1095. How would I be able to effectively conceal the knives? I was thinking about wearing baggy pants, which I wear every day. Do i need a special belt to wear on my waist since there are no belt loops on the inside. I don't care about knife laws.