Gunnar Stahl's photographs aren't really super sharp. The Nikon L35AF does have a pretty decent lens — in some ways, these cameras are a little closer to the modern Fujifilm X100 series of digital cameras than they are to the cheap drugstore point and shoot film cameras. There might be others, but since that model is currently readily available on eBay for prices ranging from $50-$120, why not just get that one?

I also think that what you're really seeing is not the sharpness per se, but the stark contrast given by the on-camera flash. Especially for automatic point and shoot cameras, the exact character of this depends a lot on the individual model — both in the flash power, its positioning, and the metering used. So, again, if you like this particular look, I'd suggest going for that specific camera. (Or the Yashica T4 Super D, which I assume you are interested in because of Terry Richardson rather than Gunnar Stahl — a little more pricy and in my humble opinion less interesting than the older Nikon.)

Stahl's overall aesthetic is casual, unstaged, in-the-moment, and lo-fi. (See his five favorite portraits for some examples.) I'd be a little surprised if he uses an expensive / pro film; that would be kind of against the whole thing. I bet it's Kodak Gold or Ultramax, or Fujifilm Superia.

Of course, the main thing you need is access, and interesting friends to photograph. From a 2017 interview, Stahl explains:

I’m mainly using a Nikon L35AF at the moment. I have a bunch of cameras that I just buy and test out throughout the year. I’m going to switch up soon.

Along those lines, I'd suggest not trying to copy the look exactly, but to find a garage-sale camera that appeals to you and experiment with it. Discover what look it produces, and decide if you like it, try some others....