I need 4 Songs Mixed

Hi, I've got an alt rock proyect EP that I need to mix. I'm uploading all the tracks on wav format to dropbox that I exported from cubase sessions. The main issue is the drums are not in sync with the songs in some parts so I'm wondering what is the best way to go about fixing them or if it would be better to re record them. I'm also wondering if it would be better to release a single first and the remaining 3 songs with the EP as a whole. I have a very good idea of the changes and sound that I need so please let me know what the budget and estimated time of elaboration would be for the 4 songs of about 4 mins each. A total of 230 tracks. Thanks :)