Connecting my Amiga 500/1200 with PC

[psxphill]

The Amiga 500 doesn't have it?

The A500 only has a mono composite output built in. However if you have an A520 modulator plugged into the 23 pin video port then that does have a colour composite output. The A520 isn't the best video encoder in the world, but you can buy one easily then plug it in and it will work.
 
Something like this would also work.
 
http://www.amigamaniac.com/RGB_to_PAL_NTSC_adapter.html

[psxphill]

2)If I use my Amiga 1200 with the RCA/Composite cable, can you also give me a link of the cable that I should use?
3)Off-topic: Same question for connecting an Amstrad 6128 with my PC. What am I going to need?

killer2k also does one, you could try him.
http://kipper2k.com/amigaforsale/
 
If you get one of these then you need an "svideo cable" and a "stereo rca to rca audio cable" to connect it to your dazzle. Otherwise if you are using the composite port on the a1200 you need an "rca composite cable".
 
just search ebay for them.
 
kipper2k was also working on a component version, which might work with your hauupage but he doesn't have that listed. You could ask him though.