Front Calipers?

[Divmiester]

Couple of questions regarding the front brakes on my 2001 - 1.4 - Petrol Multispace.

1 - are the front calipers the same on all models? i.e will the calipers from a diesel be same as petrol etc? (need to replace a seized caliper)

2 - I've noticed that my front discs are not vented, however all other models of Multispace I have come across at Scrapyards have all been fitted with Vented Discs. Can I upgrade to vented discs? 

I've noticed a few threads stating that Green Stuff brake pads are also a good upgrade..

Thanks in advance for any advice.

Regards Davie .