Welcome to the forum and congrats on the new GT! And aftermarket options are fairly limited depending on your region, but shark racing is worth checking out. They have quite a few aftermarket parts, both aesthetic and performance. Shark Racing - Search Results for "elantra front lip"
What type of lip are you looking for? Depending on what you want, you can get away with a DIY lip which can be no more than a rubber strip you can buy from the hardware store. Seen some guys do it with other cars. It looks great and most importantly protects the bumper from scrapes.