Apply and send out apps to any and all regionals. See who bites and then make your decisions. From what i have seen FO's are in pretty high demand right now so you have a good chance of getting several calls. When it comes to the sim check, as long as you can nail all the call outs and fly single engine everything to ATP standards you can pass it. Just make sure that your instrument skills are up to par because as far as I have seen that will be the first thing that will wash you out