Finding tango shoes is not easy. Most shops will have ballroom shoes, or Latin dancing shoes, which might not be the best fit for tango. Yuyo Brujo has specialised tango shoes, designed by Elena, a long time tango dancer. They are hand made in Spain in area with a long tradition in shoe making, where she’s from. The result is outstanding quality at a reasonable price.
If you are in London, you can arrange a fitting with Elena herself! I found the fitting advice very valuable, especially since I’ve never bought dancing shoes before. She knows exactly what shoes are going to be the best fit for you. I think she can offer advice over email as well.