Look for a nice rounded heel. Make sure it is comfortable and allows good circulation. Karting shoes are not fire retardant. Looking for a SFI tag is a good idea.
SCCA doesn't require a SFI rating-
GCR Rule 17.23.8
"Shoes with uppers of leather and/or nonflammable material that at a minimum cover the instep. Ventilation pinholes by the manufacturer are allowed."
I like the Finish Line Race Wear shoes.
Only race shoe manufactured in North America
Skilled craftsman in the footwear business since 1921.
Meets or exceeds SFI certification. SFI tags applied.
Top grain, premium suede or polished leather construction.
Double stitch construction in stress areas of the shoe.
Radiantex membrane between the bottom of the shoe and the sole to reflect heat from any exterior head source.
R type poly urethane "constant grip" pattern sole.
Race shoe incorporates a wear, pattern materials on the outer, frontal area of the foot where excessive wear generally occurs. The sole of the shoe is extended backwards and up over the back side of the heel to provide a "rocker area" for the foot.
Ergonomically designed and constructed, to provide positive foot feel and comfort while racing as well as comfort while walking in the pits.
Safety, Quality, Comfort & Design Engineered.
They aren't as flashy or cool as the Puma, Oakley, or Alpinestar, but they work just as well and are cheaper and comfortable.