If you are asking if the digitizer and LCD are 1 unit(like the iPhone 4), then no.... They are separate. Update: the digitizers run around $100-150 and I haven't seen any LCD for sell... You would have better luck finding someone who fixes these kinds of things locally. They are bound to have one if they buy scrap devices. try craigslist
Well.... You could possibly have some corrosion damage. If you purchased the apple care plan then take it to apple... If you want, you can disassemble your iPhone with one of ifixit's tutorials and check it for corrosion damage. you might have caused a permanent short somewhere, and that won't be easily repaired. Water damage is a b***h, I know.
Things to check: first, remove any passcode from the device then reboot then: 1. On PC - make sure Apple mobile device runtime support drivers are installed (basically reinstall itunes - put your phone into recovery mode and see if iTunes recognizes it (how-to listed below) (how-to) - Plug your iPhone into the computer - Power off the device and hold the home button down - Continue holding the home button until connect to itunes screen appears - if iTunes doesn't recognize the device in recovery mode, then move to the steps under mac instructions 2. on Mac OSx Snow Leopard 10.6.7 (probably the same on any other OSx - Try the recovery mode steps above - If that doesn't work, then check the dock connector( Link below). I hope this helps you and good luck! iPhone 3GS Dock Connector Replacement