Hey, I have a Volkswagen Golf. It's an N registration so I think that means 1996?

I recently bought an Alpine CD Reciever (CDE-988R), and the speakers fitted in the car currently are 2 crappy speakers set in the dashboard. And the front and back door speaker compartments seem to be empty.

I was recommended Alpine speakers by the bloke at Halfords who fitted my CD player. He said to keep the crappy dashboard ones for now, and put a pair of nice Alpines in the back doors, and when I want to, get rid of the two crappy front ones and put two nice ones in the front doors.

Can any of you tell me what exactly I should go for? I don't really know anything about In-Car Audio. I'm not even sure what size speaker to put in the door compartments.

Images
Back: http://img508.imageshack.us/img508/4728/dsc00509ha3.jpg
Left Door: http://img381.imageshack.us/img381/4619/dsc00510ga2.jpg
Close Up Compartment: http://img381.imageshack.us/img381/2406/dsc00511gp9.jpg
Left Dashboard: http://img232.imageshack.us/img232/3760/dsc00512ls2.jpg
Right Dashboard: http://img398.imageshack.us/img398/5750/dsc00513mw3.jpg
Right Door: http://img232.imageshack.us/img232/5941/dsc00514ca2.jpg
Whole Dashboard: http://img373.imageshack.us/img373/2940/dsc00515sm2.jpg
Rear Left: http://img518.imageshack.us/img518/9836/dsc00516pg6.jpg
Rear Right: http://img518.imageshack.us/img518/7741/dsc00517oa1.jpg
Front: http://img518.imageshack.us/img518/9941/dsc00518ay8.jpg

 

I've looked on www.crutchfield.com and found out that the door speakers are 6-3/4". Is this correct?

 

that'll be 6 inch speakers with a 3/4" lip for mounting them lol. and yes, if you have the money do alpine all around