i found this dell optiplex 755 in a scrap yard perfectly functioning{came with side panel just have it off} its ungodly slow with only a single stick of ddr2 2gb ram and
Dell Optiplex 755 SFF Intel Core 2 DUO 3.16GHz 2GB RAM 160GB HDD Desktop PC | RecycledGoods.com
Dell Optiplex 755 MT Intel Core 2 Duo E7200 2.53GHz 2GB RAM No HDD No
Dell Refurbished OptiPlex 755 Desktop Intel Core 2 Duo 4GB Memory 250GB Hard Drive 755 SFF-0459 - Best Buy
Refurbished Dell Optiplex 755 Desktop Computer by RefurbishedPC