Another guy in the JR Smith mold is Nick Young, also an UFA on a team where Ray Allen would fit,the Clippers.
Maybe S and T Ray Allen for Nick Young and Chauncey Billups, who, if he can put his Achilles back together, could be a nice backup to Rondo. He's a KG pay, and maybe the both of them would like to make a run for ring #2 together.
All these young wing players are going to have flaws, especially when compared to Ray Allen, but the Cs are going to need a big wing to complement Bradley. Young and Smith both ahve the skills and size, but both come with huge questions marks. I contend that a system like Boston, with vets like KG and Pierce, a respected coach like Rivers, and a great PG who controls things like Rondo is the best play for this type of player to thrive.