If the main reason is noise, the good cpu coolers such as the Noctua D14 can run completely silently at 12v - and if you werent doing watercooling, that would leave you more money to spend on a graphics card so you could get like a windforce 670 or kfa2 670 and have those running completely silently.
'Budget' 'watercooling' and 'silence' dont really go together. To do watercooling properly and quietly, you need to be spending a fair amount on a pump, lots of rad space and very good fans. You can cut down on noise while staying on air far cheaper than with a custom loop, and in some cases you can even stay quieter as you dont have the pump noise