Wheel size offset and what not.....

Ok so I've seen a heap of posts about wheel size and offsets and brain is just about ready to be poured out of ears.

I'm looking for some sage advice on running 15" x 9" with coilovers with adjustable ride height of 25mm to 85mm drop.

Questions:
1) Do I need spacers to clear the inner arches because of the 9" wide wheels? If yes Does anybody know what size would be good to push wheel out?

2) obviously don't want to roll any arches or any of that shenanigans so assume the 15" are ok as the standard wheels were also 15". What size of tire would look good and work for some street race / daily driver etc.

PS. Car will be totally poly bushed all round (street), front and back. And I have heavy duty engine mounts. Hopefully won't be too much of a bone rattler! Lol 😂