All will work so it depends on a few factors. If the range you expect to shoot is on the low side of 200 yards, open sights and need quick handling the 30/30 will serve for deer and bear. If longer/ scopedyou'd be better suited to pick from the 308win or 7mm08. If your buying ammo over the counter(factory loaded)then I'd suggest checking availability on the 7mm08 before purchasing and paying attention to what loads(bullets) are readily available due to the bear usage. While not hard to killbears do require a better constructed bullet then whitetails so thought should be given to this aspect when considering a dual purpose rifle. The 308win just maybea better/safe option.

If handloading then i'd take the 7mm 08, load it up with 140 barnes TSX or Nosler partition,etc to hunt either critters with confidence.

Good Luck