Need a lookup to extract data table based on four criteria & override user input

I am working on a Quote Template for pricing out hoists.

1). The user will select from four separate dropdown lists: Reeving, Capacity, Model, & Trolley. Each dropdown list narrows the data for the next dropdown list. However, I want to have a "display table" that shows available hoists as the user is progressing through the dropdown lists. In other words, when the user has selected one ton capacity, he will see a table that shows all one ton hoists and related data those hoists. Then he can select a model and the "display table" will show data for only the selected capacity and model. And so on.... I have set up the dropdown lists but need help with the lookup for the display table. See requests and exampes on attached sheet.

2). I have a separate sheet that displays technical info and need to extract data from another worksheet. The challenge is that users need be able to override the default formula. However, when the user input is erased, the formulated value should show.

Details, requests, and examples are shown in the "Quote" and "Calculation" worksheets of the attached workbook.

Thanks in advance for your help!