Which MX5 donor?

[dubzter]

So I'm still at the thinking stage of what donor to use for a build and am begining to sway towards an MX5 build. My hope would be to use an MX5 for the initial build and IVA then move onto a zetec/duratec engine.

So as a start.
What MX5 can I use to base my build on mk1, mk2 or mk3? (I'm thinkng mk1 or early mk2)

Is the running gear (uprights, shafts, etc) the same on the mk1, mk2 or mk3?

If I get a diff case from the likes of Phil at Talon can I use the sierra based build rear end?

How easy is it going to be to swap over to a zetec/duratec after it gets IVAd. Will zetec/duratec and gearbox mate to a mx5 diff etc?

I'm going round in circles and struggling to make any decisions I've done loads of reading on here and over at locost builders but my head is minced with all the variables at the moment. Think I need to decide on a route and just go for it.

Cheers folks