The way to get avionics "cheap" is to buy professionally refurbished gear, with the appropriate paperwork
http://www.seaerospace.com/
Great firm, excellent service. The downside is that avionics shops don't generally like this - those that I have used to date were very reluctant to do it, most likely because they don't get the very generous trade discount which they get on new supplied. OTOH I do know others who have managed to get it done, though usually in the context of other work.
I have no idea what is currently involved under EASA regs (and neither, sadly, have many others) but with an N-reg you need an 8130-3 form with the kit, plus the usual 337 / DER / IA etc signoffs.
As BP says, the real hassle with flying IFR around Europe is the
IR. I'd say go N-reg and FAA PPL/IR but of course there is always the risk that the DfT will try to carry out their plan to kick N-reg planes out of the UK - depriving hundreds of UK pilots of their IFR privileges and driving them back to VFR (or the IMC Rating). The DfT is due to publish a ruling on this in the next few months, I think, and the worst case outcome will finish the flying ambitions of a large number of pilots around Europe (because other countries are likely to follow if the UK manages to pull off this ridiculous stunt).
This is the longest reply I can type up on my GPRS connection before the pprune server logs me out, losing everything I have typed
