Out of all the players you mentioned, I'd love to see Chris Bosh as a Celtic.

Great player than can score in bunches, rebound and play either the PF or C position.

I also think Bosh would fit in great with the likes of Rondo, Green, Bradley, Sully and Olynyk.

I would also pick Lebron, but know that will likely never happen.

Another guy who will be an unrestricted free agent next year that I'd like to have Marcin Gortat.

And finally, there's Cousins who will be a RFA in 2014 and I believe a UFA in 2015.

Of the players listed, I would go for Lebron (obviously), Bosh, Carmelo, and Wade - in that order. Unless Amar'e has a miraculous recovery or Kobe wanted nothing more than to join the Cs for cheap, those two don't do much for me.

The other four are all franchise changing players, who, if paired with Rondo, Green, and whoever else pans out from our young guys / picks, would make for a very very interesting team. It would literally be an instant rebuild.

The 2014 free agent class is loaded with the best players at almost every position. The Celtics will have a lot of money to use this year (if they keep their expiring contracts). Players such as Lebron, Wade, Bosh, Kobe, Melo, Amare headline this years free agent class.

Full list

http://www.hoopsworld.com/2014-nba-free-agents

where this all Bosh love came from... 

he is really totally and absolutly a scrub and will not get
better from now on

I dont even want any Heat in this team, man now that KG isnt here I can even live with Melo with Rondo and a couple of other free agents (phew i said that)

It will be a tough year

where this all Bosh love came from... 

he is really totally and absolutly a scrub and will not get
better from now on

I dont even want any Heat in this team, man now that KG isnt here I can even live with Melo with Rondo and a couple of other free agents (phew i said that)

It will be a tough year

Not sure about Bosh too Sully can outmuscled him down the post in few years time...

i'm more inclined on the Center position like Cousins, Vucevic, Verejao and Drummond

for the back-up PG i like Knight and Thomas

SG should be Klay Thompson

If you want to go Superstar mode like the NETS then:
PG = Irving
SG = Kobe
SF = LBJ
PF = ZBo
C = Cousins

If you're going to go after a likely restricted free agent, I'd go after Larry Sanders rather than Demarcus Cousins (pending how he plays this season).  You should also consider that Sanders plays for the Bucks, so there is a decent chance that they will be unwilling to match a huge contract and the Celtics will be able to manufacture the cap space to sign a max free agent.

A frontcourt of Larry Sanders (VCU) and Kelly Olynyk (Gonzaga) coached by Brad Stevens (Butler) could make the Celtics the NBA team of choice for fans of mid-major schools.  With Rondo, Bradley, Green, Sullinger, whoever the Celtics draft in 2014 and whoever doesn't get sent out to create cap space.  If at least some out of Brooks/Melo/Crawford/Iverson/Faverini pan out, that's a nice team with a lot of youth and the chance to reload with several extra draft picks in the pipeline.

We can sign Paul Pierce next year right? In that case he would be my first pick. Why: fairy-tell story 
Demarcus Cousins second He could become a true Celtics imo: Though, no glamour and defender 
Andre Drummond third good match with Rajon Rondo, Sully and kelly 
Klay Thompson fourth Rajon and Klay Sick backcourt   
Gordon Hayward fifth team-up with old coach