I tried this a while back and didn't think it was worth it in the end. If I were going to do it though, definitely take a punter that can also kick. You can always lower your FG threshold, but a poor punter will cripple you in head to head human matchups that commonly involve 8+ punts. 5 yards per punt can easily cost you 40-80 yards in field position throughout the game.
side point: never lower your FG threshold below 42 yards. I learned the hard way in a playoff game when I lost because I went 3 and out in overtime and decided to go for it on 4th and 10 instead of tying the game with a FG. =)