We have had multiple questions about which affordable loopers allow you to perform verse-chorus-verse switching on the fly. The VOX VDL1 is a great option. Also, the DigiTech JamMan Stereo can work. If you go with the latter, then we would recommend ordering this custom foot-button to enable you to do this hands-free.
Only sold on Ebay:
DigiTech FABE
For details, please see the following video: