I spent a good month shopping for a sujihiki for use as a dedicated protein slicer. I cook a lot of BBQ, roasts, and my own charcuterie. I needed something that could slice raw and cooked meats, pork butt, leg of lamb, brisket, bacon, pastrami, etc.
My criteria for a dedicated slicer
1) Carbon steel - easier to sharpen and maintain
2) Long - as long as possible to make clean cuts in one drawing cut
3) Stiff - For the stuff I'm cutting that has a bark, any flex is just horrible.
4) wa handle - my preference
I searched everything from Misono swedish (330mm on rakuten was only $240) to yoshikane sld, to customs. I ended up with the 270mm kochi from Japanese Knife Imports. It's a fatter knife, so if you cut a carrot or something, it would wedge. It's really intended for protein only. So far it has just ripped through every product. I've portioned fish, sliced bacon, cutt a pork butt straight in half, sliced a ballotine, portioned steaks. Even though it is a 270mm, it's oversized and closer to a 300mm. Compared to the victorinox slicer I was replacing (too much flex, useless on raw meat), it is only about 10cm shorter. As far as length, few makers make anything bigger than 300, especially the carbon wa handled ones i like. You will find western handled, stainless that are longer. Or yanagiba (not recommended) that are longer. The market for long suji is pretty much BBQ people, and the majority of them use the victorinox granton edge slicer.
Hammered, damascus, etc cladding. Yeah it looks cool. It has no impact on performance. If you want to pay a little extra, you should get the look that you want. Personally I stay away from those, because I know that when I sharpen and thin, they'll get scratched up. I'm more about the rustic looking knives.
Anyway. that was my thought process while shopping. What you end up with should account for your preferences and sharpening skills. I wouldn't take a nice sujihiki to just any sharpener. In my area, there is only one hand sharpener using the edge pro system. Everyone else uses belt sanders, a good way to wreck your knife. The reason is that hand sharpening takes time and if people give you abused, chipped knives, repair can take a long time.