Seat and head tube angles have to be equal with your old bike for the top tube length to be a direct comparison.
Don't sweat it. Stems are one of the cheapest parts when it comes to bike fitting, and besides, what the pros use is neither here nor there. As winkybiker says, get a frame that fits, and if you aren't sure what that means for you, get a decent bikefitting first.
As for FSA, I'm always sceptical until their parts prove they work, unlike (shimano) Pro branded stuff which like all Shimano (and Campag) can be trusted on brand name. Fsa kit is often seen on branded off the peg machines as a substitution for brand/groupset parts. It isn't because it's better, it's because it's cheaper.
For sunscreen, try the P20 stuff (or higher factor ) from Riemann. It is excellent for sports. Stick it on once, let it dry, then forget.