First off, Ecomino has a much nicer sound to it.
From the OP's post, I gather he doesn't have a ton of money to blow at this time and he needs reliable transpotation that gets decent mileage.
Personally, I don't really "get" the El Camino, but, to each his own.
The trouble is that one of these things that is in good enough shape to drive every day is likely to cost more.
I think your best bet at this time is to find a decent running Ranger/S10 4 cylinder 5 speed. Such vehicles can get into the 30s with a little hypermiling/mods.
And start saving your pennies.
Some day, you'll have the coin to buy a nice old El Camino. I would suggest you get one from the 60s, early 70s, as they are much cooler, IMO. Of course, it would have to have a 396 4 bbl.
So much for eco!