I want to connect my nintendo Wii, to my viewsonic projector, using a "VGA H15 to 3 RCA / RGB Component TV/HDTV" cable.

I need 25 feet.

So, i was wondering, can i buy a 6ft cable, and then add a 19 feet "3 RCA to 3 RCA" cable?

Would that make it loose quality? What if i make that "3 RCA to 3 RCA" cable myself?

My doubts are related to the fact that i want component video to have the best quality, so i don't want to introduce any "noise".

Thanks.

As long as you use "video" cable, i.e. 75-ohm coax, it's unlikely you'd notice any degredation.

I second whoaru99 about using 75ohm cables.

Another way is to get a 25ft VGA extender. They are widely available for fairly cheap price (like at Frys here), and this way you have just one single cable running the majority of the distance rather than three cables. Of course, signal quality still depends on the quality of the cable. If you go this way, just make sure you get the right gender for both ends (easy but frustrating mistake), and look for the "thicker" looking VGA cables, because those are generally better quality than the "thinner" ones, from my experience.