Hi,
The ad700 and hd555 are open back headphones rather than fully closed back. If you want open back gaming headphones with built in mic then have a look at the Sennheiser PC 360. Unless you need isolation then I would probably have preferred them over the PC 350 as the closed back 350s do get a bit sweaty! But as I haven't tried all of the headsets I can't really say much else about them - it was only a reader review where I gave my subjective impressions, not a professional test where I could compare tens of different headsets and cards!
Let's look at your criteria:
-lifetime warranty (i think its just on card though and not headset)
Nice to have, but I'm not sure it's really a game changer for me - I'll be impressed if we're still using the same technology 10 years on, just like you're not sure your new computer will have PCI, PCI-e might not always be backwardly compatible etc.
-attached mic (i feel weird when talking threw desktop mic)
Yup, and a good quality one at that. The PC 360 also qualifies here.
-internal headphone/headset amp
Agreed, a good feature. Also present in the Auzentech, and Xonar essence STX, but not the D2/X
-and i can connect my crappy logitech 5.1 speakers + headset at same time, so i wouldn't have to crawl behind my computer to keep switching them.
Also nice, but all Xonar cards have this as long as they have the right outputs for your 5.1 and heaphones, and I think the Auzentech would be fine as you can connect heaphones and speakers at the same time.
Assuming the mic thing is quite important I think you've got three combinations to look at:
Xonar Xense One + PC 350
You've read the review. Great for music and films, okay for games
Auzentech X-Fi Forte 7.1 + PC 360/350
I've not reviewed this, but would like to

More info about the card here:
It has the headphone amp. And the X-Fi should give better gaming performance, while open back cans might be nicer if you want the PC360.
Xonar DX + PC 360/350
You're missing a headphone amp here and some quality compared to the Xense. Is that important? Yes, if you're going to be driving something like the PC 360/350. I accidentally tried driving the PC 350 without the amp and the sound was disappointing.
So really it's a toss up between the first two (X-Fi titanium HD is ruled out for RCA outputs). If you are worried about the Auzentech warranty then go for the Xonar Xense - it's a good value bundle compared to getting an equivalent sound card and headset. However if you want to concentrate on gaming then I'd strongly consider getting the Auzentech card (buy two if you're worried about reliability!) simply because the X-Fi really is a much better chip for that. But you'll be happy with either
IMHO.