Like Karlos said, it's going to cost a hell of a lot to get a Blizzard 060 PPC.
You can expect anything between 300-800 euro's, depending on how fast the PPC is and maybe Vision card included.
It's better to do little upgrades on the Amiga 1200, like a Blizzard 1230IV @ 50 Mhz, these will do around 150 euro's.
Get a CF card adapter and stick a 4/8GB CF in it.
CC-Reset fix is handy and it could be handy to install some small fans to cool the Blizzard a bit as there is no room for heatsink or anything.
I screwed 2 Scythe Mini Kaze LED fans in there, they are 40mm/40mm/10mm.
Give a bit of power with an ATX conversion cable and ATX power supply and you should be good.
I recommend upgrading an A4000 for 0S4.1 and 3.9 is do-able on A1200 with a Blizzard 1230IV.
But for OS4.1 you really need a PPC, so in the case of an A4000 a Cyberstorm 060 or PPC.
You could also forget about all of the above and go for an Amiga One X1000
