We stayed at Siesta Dunes in a 2 bdrm condo in Nov. It was clean and a great location right on the beach. It had a nice pool as well. I rented through VRBO since we were only there for 4 days. We were in Bldg 1 which is closest to the road and furthest to the beach and it was quiet and only at few minute walk to the beach. Here is their website, lots of info and you can rent directly from the management there as well -
http://www.siestadunes.com/
Good luck in finding a place, Siesta Key is beautiful!