Some is and other stuff has been misentrupided. For most panels ¼inch (6mm) acrylic is fine
the best thing to do is find the real names of the panels . As an example the IFF is called CONTROL, TRANSPONDER C-6280(P)/APX 5.75 inch by 5.25. You should be able to find a real one it is use in many aircraft and hellos on an auction site. The O2 panel that has a CRU- 52,55,68,72 several different designations. The CRU-68 I think goes in an A-10 for example most fall under MS 22062 that gives a measurement of 5.75 inch by 3 inches. The f-5 being a round for ever and in service with many countries you may get lucky and pick up real panel for a fraction of the cost in money and time of what it will take for you to build replicas. The DCS manual all so contains many of the names you need to look for panel parts indicator and instruments. I hope these few measurements help in some way all the best DM
P.S. A quick search on eBay reveiled this
http://www.ebay.com/itm/F-5-Freedom-Fighter-Aircraft-Light-Transmitting-Indicating-Panel-14-62925-5-/232037783399?hash=item3606879767:g:Un4AAOSwARZXon8b&vxp=mtr
The AN/ARC 164 radio you would need i have seen them cheaper.
http://www.ebay.com/itm/ARC-164-F-16-Flight-Sim-UHF-radio-REAL-PART-for-full-size-simulator-F16-Arduino-/122419487042?hash=item1c80c52142:g:3l0AAOSwDNdVkbiO&vxp=mtr