Others will no doubt disagree,,,but this is what I would do
1. Get some spacers from Max at Londonfixie
2. Get the following from Charliethebikemonger or similar
Surly rear cog
KMC SS chain he sells...plus maybe a half link (if you are going for
the magic)
Surly Front ring (or any other non-ramped ring...Gusset?)
Some sort of chain tensioner (if you are not going for the magic)
You might need some narrower chainring bolts.
Think thats it.