4 mile trips.. most any decent saddle will be comfortable as long as it fits your butt IMO. 20+ Is where you start finding out if your saddle is really a good fit though, as has already been said Brooks are made in England and if cared for right water isn't too big of an issue. You also didn't give us a price range, or an idea of how wide of a saddle you prefer, so I shall simply throw out a few cheap saddles that I personally like.

One is the Origin8 pro uno's, they sell for about a whopping 20 USD, look decent, almost light, and very comfortable, the rear section though is quite narrow as is the nose etc, so if you require a wide saddle probably not for you.

There's a few specialized saddles that can be had from LBS used bins often for cheap that are quite nice and a bit wider, if you take the time to look and have an idea of your width you should be able to come up with something via that route.

Now a little devils advocacy: Why not drop the money on a good saddle? Brooks can be found used or on sale for less than 90 USD, sometimes for almost nothing even, assuming you buy used and at a good price even if you don't like the saddle you should be able to recover your costs.