Sun has been a long favorite of ours as a great hardware platform, because of their commitmenet to open source. They are working the startup arena these days, and have created a service to help new technology startups. They offer discounted servers, open source software, and co-marketing help. If you are just planning your architecture, we really recommend taking advantage of their offer. They are sincere, ready to help you. They also now own MySQl. Pretty darn good.