It's really funny, but only if you've kept up with the whole design growing pains of that inferior system. They had the chance to make a great rifle and screwed the pooch.
That's not the best area to have a transaction of any sort really. Good shot under pressure, most probably would never get that off. I will be interested to see the outcome of this case.
This is one of the main reasons I got out of the shooting industry. I was a bullet sponge once and now people are dumber than ever, especially with the influx of new gun owners out there.
My vote is the Sig. Then you have the best of both worlds, your HK and a Sig. I would go for an older model, say 05-07. FN makes a nice rifle, but I was never thrilled with their handguns.
Stay away from the 250.
There is a guy by the name of Rob at River's Edge that has a large knowledge of Case knives. I would email river's edge, or better yet go and visit them.
http://www.bladeforums.com is another decent site for info.
I think your best bet is to try and find some on forums and such. You can usually stretch a few more dollars out of something if you're in a crowd of people who respect and actually want the item. There has to be a site dedicated to V6 --> V8 conversions.