Something in a 165/70 to maybe 185/70, maybe even 75 or 78 series to get the height. Depending on ride height & wheel offset, 27"-28" is about max tire height before you need to trim the bottom front corners of the wheel openings.
Back in the day we ran VW Beetle size on 4" wheels, which was something like 5.60 x 15; my drag car runs 7.10 x 15 Morosos on a 3.5" wheel, so sizing is approximate at best.
You can play with tire sizes at discounttire.com if you look around on their website, they have a comparison chart you can plug different sizes into.