How to Get Smart Shoes in "GTA IV"by Julian Vargas ; Updated September 22, 2017
They say clothes make the man, and in "Grand Theft Auto IV," this is as true as ever. Characters throughout Liberty City will react to you in different ways depending on your threads, and some may not speak to you if you're not properly attired. You can spend your hard-earned money at various clothing stores throughout Liberty City to build a respectable wardrobe. Your outfit is particularly important in missions that require you to wear "a suit and smart shoes," such as any missions done for Jimmy Pegorino.
Drive to either one of the Perseus stores in Liberty City. One is located in Middle Park East, at the corner of Pyrite Avenue and Bismarck Avenue. The other can be found at the corner of Amethyst Street and Amsterdam Lane in the Exchange neighborhood.
Enter the store and talk to the clerk. You need to purchase a complete suit of clothes, including wingtip shoes. All elements of the outfit must be purchased from the Perseus store and it will cost around $1,500 for the entire outfit.
Remove any headgear, including glasses or masks. Wearing headgear marks the outfit as not being wholly from Perseus, thus the game will ask you to wear "a suit and smart shoes" when you attempt to undertake a mission that requires them.
Drive to Jimmy Pegorino's marker on the map -- a gray J signifies his missions. So long as you have not altered your outfit since purchasing it from Perseus, the mission will begin as normal.
- link GameFAQS: GTA IV