1.c4-a reversed sicilian kan?

I play the sicilian kan as black but I dont know what to play as white. Im thinking about playing 1.c4 and then trying to play the sicilian kan as white. Is the extra tempo useful for white or would it be better to play a different variation of the sicilian reversed like the dragon or najdorf?

1) Many people will not answer c4 with e5. Nf6 is even more common but also c5 and e6 are very popular. Because of the many possible replies and many possible transpositions the English opening is one of the most difficult openings to play. When playing c4 you can expect anything from hedgehog to catalan to kingsindian.

2) The extra tempo does not work in whites favor. The setup you posted is almost equality for black.

then what should I play as white? 

1.c4 is the English opening,quite complitated.
Play 1.e4 as white. 

That depends on many things.

• How old are you ? If you are young consider e4 as it will help you most forward in your chess career.
• What type op positions do you like ?
• What do you want to achief (theoretical advantage means mainlines but you can also cut down on learning by using less popular openings that may not give and advantage with blacks best reply)
• Look at the GM's where you think.. hey i want to play like that and check their openings.

This is definetely possible. Not only can you play a reversed Kan but also a reversed Taimanov and reversed Najdorf is also possible to play with 1.c4. But the big downside is that your opponent has to play Nf6+d5 for it to work. I get a lot of 1.c4 e5 but I'm only 1500.

1.c4 e5 is the most common move against 1.c4

In practice e5 you will get e5 in about 1/3 of your games. Atleast accoording to my database

1.c4 and 1.Nf3 are so broad, basically you want to know a load of different positions/transpositions if you are to play either, can't just assume you're going to get a reversed sicilian.

Sure, but Black is not going to play the same moves as he would playing White up a tempo.  So you are not necessarily getting an advantage from your "reversed defense" opening.  For instance 3...d6 is possible with the idea of a reversed KIA setup ..Nbd7 ..g6 etc. where the a3 move doesn't make a lot of sense.