ok I know this has probaly been asked before so dont flame me!!!

I have an 04 WRX with 20,000 miles on it. And I want to do an oilchange this weekend, right now the car has regular oil in it and I want to switch to synthetic.

My questions is can I just go ahead and switch over to synthetic, or should I go blend first then move to synthetic???

Also what type of synthetics do you guys recommend?

And in refrence to the oil filter... I was goign to go with the K&N Oil Filter (I have used them in teh past and was very happy) but it doesnt come with a new crush washer.. Do I really need to get a new one??? I ask because my friend has been using the same one for liek 3 years now.. LOL

- Mike