Component Y/Pb/Pr is better than both S-video and composite. It supports higher resolution, and progressive scan (480p,720p,1080p). The Y is luminance and sync signaling, the Pb is blue minus, and the Pr is red minus. Since its progressive, it uses more bandwidth than the former's.
It's easy to get "component" mixed up for "composite"/"rca". Component is the Red/Blue/Green cables, composite (or RCA) is the Yellow/Red/White cables.
The S-video and composite were made for standard definition video, which is lower resolution interlaced, as opposed to progressive. interlaced video has less bandwidth needs.
Normally you would use Component when you have it available over composite and s-video alternatives, but don't yet have HDMI capabilities.
If you can use HDMI, it is better than component, since HDMI is digital, component is not.
The goodwill I found is one good source for VCR's. The Time-sync ones, which you need, are about $400. Too expensive, when you can get a scaler that has the same frame correction features in it on evil bay for cheaper. I got one used for $45 (Extron System 7SC, uses Composite, up to 1080p). The VCR isn't as important as its head is in good alignment (take the cover off and adjust it if not) and VCR has more than a few decent heads on it.
Logically, if you can snatch a good deal on a VCR that has component, then make sure your scaler (or cap card if not using one) has component input. Scaler's with HDMI aren't really useful for VCR capture IMO. Im also not sure the component ones are in fact either, since its possible that somehow they have upconverted the signal to make it component, which you can just eliminate, and run it straight into your scaler with svideo or composite.
Out of the scaler it can be scaled up 720p/1080p for raw capture. So if your capture card has component in, then make sure the scaler has component out. I'm still a bit yellow in the area if the RGBHV on the back of my scaler can be converted to Y/Pb/Pr easily or not, im not sure. Im testing instead using composite out of scaler, to composite in to USB capture. The results are maybe more low light detail than the S-video signal, so it has its benefits.
Look for one that takes care of the frame corrections for you, so that you wont have sync issues, when you capture (VirtualDub/HuffYUV I assume?)