I'd suggest a cabling contractor. Seriously. It helps to get some ideas of what other installations look like, and they can help guide you.

In your case, you probably have HP 10642 or 10642 G2 racks.

To answer your questions...

  • Standard practice is to place your top-of-rack switches and patch panels at the rear of the cabinet. You didn't specify the particular types of switches in use. Please provide that information.

  • Depending on your switch models, they may pull air in from the sides, rather than the front or rear of the device, so place them where it makes sense from a cabling and servicing standpoint.

  • Don't place your patch panels on the front of the rack if you have a choice. You totally want to avoid this situation before it gets too unwieldy.

  • You don't necessary need to keep power and data cables separated, but it's probably good practice to do so. For your power cable situation, buy short power cables.

Some examples...

Front view - Data center fiber patch panel in front. All switches and router rear-facing. Servers are front mounted. enter image description here

Rear view - Switches and router are rear-facing. Cabling run in channel behind rear vertical rails. enter image description here

Another front view. Switch chassis is mounted along rear rails. enter image description here

Another rear view. All patch panels and cabling are rear-faacing. enter image description here

Use appropriate length power cables to connect to your power distribution units. The location of your servers' power supplies shouldn't matter since you can run the right-sized cable to the PDU. pic