GFI - all created equal?

[mr_alberta]

I was at my local Home Depot today and was looking at some of the GFI outlets they had. They had ones ranging from $11 to $20. Now my question is, are they all basically the same? Is there anything in particular I should look out for in a GFI (i.e. rated 15A or rated 20A, etc).

I also noticed some have an indicator light on them. Do you find the indicator lights on these outlets useful or should I just save the $2 and get the plain old one? Also, are these outlets easy to install? The only wiring I've done is to hook up my ballast and lights.

Thanks.