I've seen a lot of Vinyl for cheaper, but I went for the 3M stuff as has been told it's the best stuff by a long way. I had to lift and re-stick it in numerous places several times and it never lost its stick, which I've been warned the cheaper stuff does. As I was an amateur I decided to go for that stuff as I guessed I would be lifting it a lot.
As for the sunroof and ariel; I removed the ariel completely, which took all of about 20 seconds (using the Haynes manual. I then opened the sunroof and stuck it all down. Once I had got it flat and laid I cut out out the sunroof hole, leaving about a 4mm edge which I stuck down (using heat). I then cut n X over the hole where the ariel went and reinserted it.
I kinda guessed the sticker wouldn't be to everyone's taste, but I like it so I'll keep it for now. I spoke to about 5 sign writing companies that all wanted similar prices to what I paid, but I've still got a load left over. I've now done both mirrors and have enough to do the bonnet if it takes my fancy. I bought 2x3 metres.