Thoughts/Recommendations on bed cover?

I definitely want a bed cover for my SR5. So many options out there it's sort of overwhelming though. Was thinking of going with this one (price is a bit high, but if it lasts and is good, I'll suck it up)
http://www.autoanything.com/tonneau-covers/bak-backflip-fibermax-tonneau-cover

My considerations:

• I typically won't be hauling things where I'll need the full bed without the cover. Occasionally, yes, but it won't even be a monthly occurrence.
• Want it be relatively secure. When traveling with the family will need to store luggage in there, so I'm thinking this leaves out the vinyl roll-up ones.
• Prefer it to be strongly leak proof. I don't have to worry about snow in Florida, but it rains hard, and often, here in the summer.

I'm also considering something like this full cover, but if I do ever need the full bed, like for hauling furniture, this looks like it would be a real pain to remove http://www.autoanything.com/tonneau-covers/61A7578A0A0.aspx ?