Not understanding why you need a pvr card to tell the truth.
But then again you should give some details on what your source video is, and what you want your destination to be.
I'm going to assume that you're going to be going DV quality, mainly because you say you're going to be posting to YouTube - and to be honest it's good enough for 99.9% of anything shy of professional production - so unless your output is to BetaSP or DigiBeta, you're not going to need anything over that.
If you're going from a digital camera - most have firewire or usb and you can import your video directly to your PC (if you don't have a firewire card - they are dirt cheap)
If you need to go from composite, you might need to get and analog to digital converter - these are getting cheaper all the time - I've seen some as low as 50 bucks.
There's plenty of editing software out and about ranging from free - to cheap - to expensive.
I think Avid still has a free version of it's DV Express software, it's a very cutdown version of Avid, but is still very capable and I've recommended it to many people wanting a free way to edit videos for internet streaming.
If you don't need to output it directly to a tape - it's actually a great free solution.
Unless the object is to actually edit it on the Amiga for the retro-coolness factor - in which case go that route.
If it's for anything else, honestly - you'll do it twice as fast, and half the headaches following the above.
I'm a professional video editor - and if you need any advice on the subject, feel free to send me a PM