Urchin and Algae cleanup advice

[Sun Devil]

I am considering the purchase of my first urchin this week and I would love to have some advice. Currently I have a 5 year old tank with mostly LPS and some shrooms. Fish consist of 2 false percula, coral beauty, with serpent star and blood shrimp as tank mates.
My urchin consideration stems from a strange algae problem that I cannot seem to find much info on. I have a bristly algae (similar in coarseness to shaving bruch, but not uniformed shape) that grows from my live rock, especially in areas of great corraline growth. It actually grows from little "stems" to protrude from the rock. Its foundation to the rock is so strong, that pulling it jeopardizes my aquascaping. I have not been able to find it on any website, and solicited for info here to no evail. It is becoming quite unsightly to say the least. My tank levels are great as well, so I am not sure how this stuff is coming about.
I would like to try an urchin for the removal of this stuff. I am just not sure which one. I am not too worried about my corraline disappearing as I have to scrape my front glass weekly to rid it of corraline. Any suggestions? Remember, it is my first urchin. My tank size is 115G
:spin3: :spin3: :spin3: :spin3: :spin3:

[Grey Reefer]

I would get a Pin cushion (Lytechinus vaniegatus). Great for a cleanup crew alot more active than Tuxedo urchins. The will it marco, micro, and coraline algae. The spines on the Pin cushion are more robust than other urchins so they want stick you as easily. Be forewarned though any urchin will plow through coral that is not secured to rock, because they are basically bulldozers.

[Sun Devil]

Great thanks. Will there be any problem with compatibility with my serpent star? The body of the star is abou the size of a quarter.