Would it be a bad idea if ...

I bought one of those chrome cold air intakes off of ebay ?

Also if i got a throttle body spacer would it fit with the cold air intake and it worth the money ? Also which one would you recomend for both ?

Do a search...theres quite a few threads on the ebay CAI.  Basically, to sum them all up....the cold air intake is only as effective as the heat shield you make for it.  The cheapest kits on ebay do not include a shield, and are therefore a negative impact on your preformance.  If you effectively isolate the intake from the engine bay heat, you will get a decent result. 

The general feedback from people installing these on our trucks is that it makes the sound much better intake --> exhaust.  Same with the throttle body spacer.  Not really any gain from a TB spacer, but it does seem to improve the noise you hear.

To me, neither is really worth it simply because of the cost, but alot of people will swear by 'em.  Make your own decisions with the info from your searches