Silicone insulated wire is usually used as ignition wiring due to its higher heat resistance. It is also more flexible than Teflon.
I also just read that silicone insulation will burn if held in a flame, and continue burning. Teflon will melt and burn if held in a flame, but will stop burning when the flame is removed. That is why it is used for plenum rated cabling in building construction. IIRC, Teflon is more abrasion resistant.
If you are concerned about a possible electrical fire, I would go with the Teflon insulated wire.