The most difficult part of completing CoP is finding 6 people that don't totally suck. The second most difficult part of completing CoP is finding another 6 that don't suck and that have jobs that are capable of completing the BC fights and showing up on a regular basis.
There is no need to start CoP if you don't intend to finish it. After you have finished the initial promy missions and have access to Lufaise Meadows you are done with reward #1 out of a possible 3. The other rewards are getting to 8-1 so you have sea and limbus access. Reward #3 is the ring you get after completing CoP. Another mini reward would be the earring you can receive after finishing a few other fights but it seems not many have interest as I haven't found a party for those.
I would say gather a group but with low expectations. It took me 5 different static groups before one stuck together for more than one mission and we went 1/1 on every single mission after Promyvion-Vahzl, about one week at a time.
Don't bother recruiting anyone that doesn't have a level 75 job or is very close to having one. There are a lot of uncapped fights you can drag them through but eventually you will be required to do some difficult uncapped fights. Anyone with multiple 75's is a plus of course. Anyone w/o a 75 job I would say is less likely to spend the time and effort to complete the missions.
I do know 2 people that made it to Promy-Vahzl before their static party fell apart but I highly doubt they would want to go all the way back to 2-3 to help someone due to the high rate of parties breaking up after a few missions.
My suggestion for a party setup would be:
Player 1: Pld and Nin
Player 2: Whm
Player 3: Rdm or Bard
Player 4: Blm
Player 5: Melee DD
Player 6: Melee DD
My party setup was thus (Promyvion-Vahzl to the end):
Gilberto: Pld (Nin at 60)
Delectur: Rdm
Cable: Whm Drk
Mrtictac: Mnk
Skibum: Blm Rdm Bst Smn(65)
Upsidedown: Blm