I have the old King of Bretonnia model and My army is led by Lord Garlervere: Lord of the Flaming Talon. I want him to ride a phoenix, hence flaming talon. What bits do I need to make one and how should I do it? I would like to use at least some bits from my old hippogryph to save money. Great Eagle? Empire Griffon? What?

And any conversion tips would be great.