I'm sure this isn't the first time you've heard this, but you might try making adjustments to you saddle position (and maybe the saddle itself) to address the numbness issue. Sounds like it's hitting you in the wrong place if it's cutting off blood flow. If you're considering touring it might be worth $80 on a brooks - or whatever it takes - before setting off a thousand miles. Or ten thousand.
I found that after riding a hundred miles or so on one tour I nosed the saddle down maybe 5 degrees and there was a substantial improvement.