AS is a carbon steel known for its edge retention, you should be aware that the Asai slicer you linked is AS carbon steel. They do have stainless Damascus ones though, here is one: http://www.epicedge.com/shopexd.asp?id=87922
I happen have a petty from that line, one of my first purchases. I strongly dislike the bulky cladding and the use of Pakka wood because it makes it feel cheap. Given all that, it does have one important quality that makes it a great cutter: it has very good geometry. I still feel like I paid too much for it though, and it was considerably cheaper back then (as were all knives).
Unfortunately, in my experience, good Damascus tends to be very expensive and cheap Damascus tends to fall somewhere between less-than-ideal and crappy. So just be prepared that a well made large knife in high quality stainless damascus will be somewhat pricey compared to a similar mono steel knife.
The R2 Tanaka really seems like a perfect fit. A Yoshikane SLD damascus is another possibility here: http://www.japanesenaturalstones.com...40-m-p/467.htm
Since you seem to have been prepared to spend $800, why not get that knife and spend less on the slicer? The Hattori HD slicer, for example, and the Tanaka gyuto come in right around budget.
Personally If i were purchasing a stainless slicer I would strongly consider a mono steel knife with good geometry and a high performance stainless, like a Gesshin Ginga or a Ryusen Blazen.
There's many combinations of options and I'm sure others will weigh in with some opinions.
Afterall, You're in good hands here if you need help spending money!