Personally, I'm not a fan of gravel slicks. I have used several that I liked, but I found them prone to punctures on the road. Since you're looking for road oriented tires, one I would suggest is the Donnelly Strada USH. They come in a 32 and 40mm.

I use the 32mm tires as my winter road tire (on my gravel bike). These are not lightweight slicks, but more robust gravel tires suited for roads and smooth gravel. I've been using them for years and never had a flat. They roll really well, but of course have the disadvantage of being a little heavier and stiffer than most gravel slicks.

Also, if you are using a latex sealant, consider getting a Stan's Dart tool to help with punctures that the sealant cannot handle alone.