iPod touch GPS

Hey,

I'm going to rome in 20 days with friends and I'm taking my ipod touch with me together with my wireless bluetooth gps receiver to see my location on my ipod touch.

The only thing is that i need a good app to use which has maps directly saved in it without needing a wifi connection to download them in the app itself while using it (unlike google maps which downloads the map) & still able to use my gps receiver aswell with it

any suggestions :)?