Originally Posted by
Stan Evil
You can find the requirements for IFR instrumentation in Part-NCO. For an IR, from a nav-kit point of view you'll need VOR/ILS/DME, mode S transponder, 8.33KHz radio, plus a GPS that is 'approach certified' - such as a panel mounted GNS430W. The aircraft POH will need to have the certification of the GPS included as a supplement. The last 10 hours of a CBIR must be done at an ATO; if your aircraft meets the spec then they will probably be prepared to put it on the books.
For an IR(R)/IMC rating, the aircraft only requires VHF radio plus a VOR and ADF, but you won't learn much with just that equipment.
Read CAA Standards Documents 25 (IMC), 1 (IRT) and 7 (aircraft approval - this is out of date, but it gives you an idea of what the examiner will expect)