An input selector that I believe is well built and won't break the bank is the Niles AXP-1.
http://www.amazon.com/Niles-Black-FG00002-Auxiliary-Selector/dp/B00006I5J0
http://www.amazon.com/Niles-Black-FG00002-Auxiliary-Selector/dp/B00006I5J0
Preamp w/ Single Line Input. But I have DAC and CDP