I have yet to purchase a GPS and start geocaching, but have been trying to educate myself from this site and have narrowed down my purchase. I think I want an Oregon, but don't know if I should get the 300 or 400t. Primary usage will be geocaching, but want to use for auto nav too. For geogaching, will having the topo maps be something I will really need? We have a 2 1/2 year old that we will be geocaching with, so long hikes aren't in the picture for the next few years for us. Also, should I go ahead and get City Navigator software? Sorry if these seem basic to experienced cachers, but without having done it before I'm not sure what to get. Any comments will be appreciated.