I like #3.

Extending the hardwood to the front isn’t an option. We would have to sand & restain 1800 sq ft of wood to match it as it’s 8 years old

We added hardwood to our existing 25 year old wood. A professional installed and matched the new floor. You cannot tell the old from the new.

I like yours if that matters, I doubt. ;) but slate will darken the area, and contrast much with white, which is ok. If nearby walls are sage green, and floors walnut-type, your toasty tiles are a nice look.

From the photo your house looks fairly traditional. Of the three choices I like the third one best. It has a natural stone look and a warmer vibe.

Stick with the 12x24, the others are too large for the space.

How about a creamy beige/taupe tile rather than gray.

We are renovating the whole house so will be sanding and restaining existing hardwood. Beige/taupe isn’t really in our colour palette

I liked the idea of 24x24 for a front hall because I don’t like grout lines

The slight gray concrete slate can be difficult

Agree with the taupe comment with the colors from your other room. Pretty!

Number 3...and consider a diagonal layout pattern.

If you go with tile, I like #3. You can do a darker grout so you don't see the lines as much. But you also say that you're sanding and restaining all your hardwoods as part of your remodel; can you lay wood in your entry? From just seeing the one picture of your entry, I think extending the wood would look really nice. What does the flooring look like on the other side? Can you stand at your front door and take a pic?

If you live in a 4 season climate, hardwood is not ideal at the front door. I'd also opt for #3 in a classic brick pattern. You should be able to find out the grout colour used in the sample (it's usually labeled on the back of sample), and the tighter the spacing the better especially in a high traffic area like an entry.

Good luck with your project!