I'm fan of Jan approach and I currently own an Corda Jazz I'm very Happy with. This amp drives easily and perfectly all Cans I try with. Even old AKG like K1000 , K340 ou K240 monitor/DF/Sextetts. My HD800 sound great with the Jazz.
Unfortunately . I have to sold it in order to pay the DACCORD. My MG head does a good combo with HD800 and I hope the Daccord will compliment perfectly my HD800 rig.
The final purchase will be Corda Classic ( or maybe a Jazz again) a few time later when I'll be able to save enough money. Then I think I will not have to change anything in my basic rig for years. Indeed, I think that with a complete meier gear + My Old powerful tube amp , I would have to spend a lot more money to get subtantial upgrade. I can't realy speak about "end game" gear because to be honest I must admit that this game has no end.