Only recently has launched the website GetiOS.com that aims to facilitate the user to search for a firmware specifically for iDevice.
The operation is very simple since we only have to select our device, the model and firmware you want to download. In this way we avoid unnecessary searches by Google.
The developer of this web page also has Jailbreak Wizard that tells us if there Jailbreak for the device and whether it can be released.
Source: iPhone Italia