I consider dreamhost and bluehost on the same overselling level as every big hosting services out there. Small host will provide you more friendly and better support imo.
Anyone here ever heard of amazon ec2 ? The offer from amazon is amazing: "a virtual machine is roughly equivalent to a system with a 1.7Ghz Xeon CPU, 1.75GB of RAM, 160GB of local disk, and 250Mb/s of network bandwidth (bursting to 1Gb)" and cost $0.10 per hour ($72 per month) plus bandwidth cost. You only pay as you using it. It's a shame that it is still in closed beta.