depends what you want to spend. some are 10 bucks at the parts store, some are upwards of 100 bucks. anything is really better than the stocker.
install is easy if you are a little familiar with cars. run the sender, relocate the stock gauge's sender if you want, and mount your new gauge.
if you are not sure, you might want to grab a buddy and ask him if he knows to how to it; gives you a safety net.
good luck.