A while back these models were available for download, but the link got taken down. This was posted by @Olivercomet in 2017. I was fortunate enough to still have this saved, so I decided to reupload them again for anyone that wants to port them. All the files are OBJ, and some of the poses aren't all 100% T-Pose, but there are ways to go around it and it can be figured out. It's a total of 35 characters, feel free to port these characters to any GTA game! 👍
Download: https://www.mediafire.com/file/0ohqg34v4utdxpk/BTTF_Character_Models.rar/file
(Note: If the link ever goes down, remind me to reupload it again.)