Something which I discovered today which I am sure many partners will find useful is the Horizon Sizing Estimator tool. This is located at https://developercenter.vmware.com/group/dp/horizon-sizing-tool this is available to partners only I believe. You can use the free lakeside assessment tool to generate the assessment data either via the free cloud based tool http://assessment.vmware.com or the free on site version.
Using this tool you can then generate a XML file which is then fed in to the sizing tool to help size your customer’s environment. You can also manually specify a whole ton of other variables.