Considering to buy "Theory of Poker"

But I'm wondering whether I should buy Hold'em for Advanced Players instead. Which one would improve my game more? I am a small stakes limit Hold'em player (successful at $.5-$1)- I basically want to move up limits to $1-$2 or even 2-4. I was thinking that Hold'em for Advanced Players is the same thing as TOP except HFAP is written excusively for hold'em. Or do both these books present different ideas? Any comments appretiated. If I do decide to buy both, which one should I read first?