Ok, this is just my suggestion. Mind you, I enjoy using an All Eevolution team on-line.
1. Decoy - Required to have a High Def, as well as healing-type moves, and possibly attacks that cause status changes to opponent
Leafeon level 70-100
Grass Whistle
Sunny Day
Synthesis
Giga Drain
FYI... on the decoy, I like using the move PROTECT to see what hard hitting moves they have, and the stall never hurts... its just a matter of discussing whether or not you like using Protect
2. Warrior - High Attacker, nothing more. Do damage as fast as possible.
Flareon level 74-100
Fire Fang
Bite
Fire Blast
Iron Tail/Sunny Day
(physical sweepers, you need sweepers as it is. At least Fire can take down some pretty serious tanks such as Forretress and Skarmory)
3. Warrior - Same as stated above. But this time, it will be Special damage.
Glaceon level 74-100
Blizzard
Mirror Coat
Hail
Hidden Power/ Ice Beam
(if you were to do all physical sweepers, remember that a physical wall will ruin that concept... and it's always nice to have a backup plan... I'm not too partial to Glaceon.. but a stabbed IceBeam is a serious force)
4. EV Trained - You want someone who has naturally high stats, like high HP or S.ATK. That way, you get more from EV training. At least, that's my take.
Espeon level 74-100( EV traing for S.ATK and Speed)
Future Sight
Psychic
Sunny Day
Morning Sun
(enjoy the EV training, it pays back 10fold over time)
5. Resistance - This is where the Eevolutions have a slight problem. They each have their own weaknesses, and only one has the most Resistance, but s/he is already in use, Flareon.
Vaporeon level 75-100
Aqua Ring
Brine/Haze/Acid Armor
Rain Dance
Hydro Pump
(Vaporeon is only weak against grass and electric... another good Tank is umbreon... because of his immunity to psychic and overall great defenses)
6. Tanker - The big guy. The head Honcho. The one no one messes with. The one who will beat you with a lead pipe and tell you to like it.
Jolteon level 80-100(Head Honcho must be highest)
Hidden Power
Rain Dance
Protect
Thunder
(you can always use Baton Pass on a Jolteon... if you learn to switch in on an electric attack aimed at Vaporeon.. BAM.... and you can always bass on agillity)
Now, let me explain Jolteon's odd move list. Rain Dance lets Thunder always hit. Protect can help save your hide quite a bit, but you shouldn't need to use it unless you fight someone faster. Hidden Power should be something decent, like Ice or Ghost.
Sorry if this is not what was asked. I couldn't quite understand what was asked.