What kind of medieval armour and weapons can you make using today's sciences?

[Telok]

And the OP says nothing about restricting chemistry. Only electronics.

Then you've got modern arty with a steam engine and zeppelins with machine guns and howitzers. Bombs of RFNA and elemental flourine, nerve gas, v2 rockets. The megafauna will either sit down and play the civilized people game or go extinct, no questions asked.