I am clueless as to Which to get.

All I want is a knob that i can turn for volume control... nothing more. I also don't want a huge one like the Griffin Powermate.

I was looking at:
http://www.phidgets.com/products.php?product_id=1052
which is direct USB but the actual knob is very small.

then I looked at this one:
http://www.phidgets.com/products.php?product_id=1116
but it would require me also buying:
http://www.phidgets.com/products.php?product_id=1018
to get the USB connection. (pricey but more along the sizes I want)


Now here is what I want to do so we're all on the same page. I'm making my carPC a music player only with a 4x20 LCD display in the ashtray (flip the cover open to view the screen, otherwise it looks normal) and use the actual Lighter as the Knob for the vloume control (also keeping it "hidden") now i don't think i can use the plastice part of the lighter as a knob on the first device that i showed as it might be too small. is my only other option the 2nd one I posted? does anyone have other options?