Hi Andy
We are currently having great fun refurbing a 16' Phantom / 90 Yamaha to race in OCR in 2009.
1. 2 pack / fibre glass etch primer.
2. It depends what you are going to do with the boat but you would need deck supports to mount a kick board.
3. Wilks -
http://www.wilks.co.uk
4. You should be able to get a new screen from
http://www.phantomuk.co.uk
5. A 2 stroke 90 is a great combination for the 16' Phantom - have you tried
http://www.boatsandoutboards.co.uk Keep looking they do come up quite often.
6. Fibreglass from behind to re-strengthen and then fill and respray.
If you have any more questions, please feel free to pm me.
I hope this helps.
Good Luck