720p@30fps, 2000kbps, x264 Veryfast.
1080@60 isn't going to work on 3500kbps, and even if it did almost everyone trying to watch at that bitrate will buffer like crazy. Your CPU also isn't strong enough to run 1080@60 on Veryfast (or 1080@30 for that matter). i5s generally run out of gas after 720@30 anyway.