Custom diagram software needed

I am looking for someone to make me an application that I can easily create diagrams for my facility. I run a engineering room where we do a lot of connections of various types of hardware, and I would like a simple application, that can work on mac or windows, where I can create hardware to be put into a database, and then I want to be able to drag and drop the hardware onto a grid style page and then make wire connections to the device inputs/outputs. I have been using omnigraffle for this, but there are too many options that need to be learned for it to be used properly, and I want something simple that anyone can learn how to use very quickly. The main problem that I have is when I add lines to make connections, there is no clean way to show the lines when there is many connections from one device, each connection should have its own connection point to a module. Additionally, I would like the ability to also track inventory of the hardware on a separate section. So every diagram with a specific file name, can be inventoried, so that I could see how many devices or each module that I have manually created are in the entire file set. See the attached example diagram, example device. This device in the example, I had an image for it, but for other devices I may not have an image, so we need to use squares. When creating a module Here is the breakdown of how I create the diagrams: Set boundary box for Location A Drop hardware/modules into location A Set boundary box for Location B Drop hardware/modules into location B Set connection method for location A and location B Then I make connection between modules are each location. -------------------------- Each hardware or module has two options. Input and Output. Inputs are always on the left side of the hardware/module icon and outputs are always on the right side of the hardware/module icon. Each module can have various types of inputs and outputs. Each type of outputs should be set in the preferences section of the applications. i.e. Analog Video, HDMI, SDI, ASI, RF etc etc..... each one should be a different colour, and used as a standard throughout the application. Once the hardware/module is set with its inputs and outputs that becomes part of the inventory of hardware that we can drag and drop from the inventory drawer. Ideally I would like it to automatically space and make the lines look nice. Lines should not ever overlap hardware or modules, the lines should automaticly go around an item if there is something in the way. See attached images for a better idea of what I am looking to do.