I use this one from Home Depot/Lowes. Its cheap and easy to use. Cures in 24hrs, but most people wait 48hrs. It says Windows/Door/Attic/Basement on the tube. Make sure it is the "I" not the"II"
i use GE type I silicone on all the aquariums i reseal and the sumps i do as well. never had a problem. from what i understand, type I does not have the anti-fugal stuff in it. i have been using if for over 4 years now and have never had a problem.
I use the Silicone1 for sump baffles, but if I was doing anything structural I'd use the RTV silicone adhesive instead as it is much stronger and still safe. It is still GE but it's the Momentive line. There's a clear and black version too.