London or Trompowsky

Which one would you play if you were white.

It was a question mark not a period

Trompowsky wins and it's not even close.

ok but London is more fundamental

thanks for the idea

Depends on Black.

1...Nf6 - Trompowsky

1...d5 - London

In fact, I don't play the London these days. I play the Veresov.

1.d4 Nf6 2.Bg5 and now if 2...d5, then 3.Nc3 (Veresov) - Otherwise Trompowsky.

1.d4 d5 2.Nc3 Nf6 (If 2...e6 or 2...c6, then 3.e4) 3.Bg5

Not really. It doesn't fully occupy the center with pawns. It doesn't develop that rapidly either... It's really just boring. Its endgames aren't even that interesting. 
If the goal is to focus on fundamentals just play the queens gambit.
For what to pair with the Trompowsky, an alternative to the Veresov is the QGD modern. Trompowsky can transpose into it in various places.
Another option is the Torre attack. Trompowsky can transpose into that also, after 2... e6. The pawn structure is the same as the London, but the bishop pins the knight. You can reach that via 1. d4 d5 2. Nf3 Nf6 3. c3 e6 4. Bg5. The move c3 here is a waiting move. It allows you to choose what to transpose into based on blacks next move.
For the Torre, I recommend waiting until e6 to play it. It's not great against d5 by itself. It's not great against g3 either. The e6 line is its best one. That's the line the Trompowsky transposes with. One option is to play the London when black doesn't play e6, but instead plays g6 or c6. In other words, you don't have to play the London in every line. You can mix it with a Torre to round out a Trompowsky repertoire.

Trompowsky.