I've done a number of recipe's with Citra Hops. I don't really feel like it's a "lemon" taste but more citrus like a grapefruit. I will say that if you use WYeast 1056 American Ale for your yeast, add the Citra late in the boil, say 20 minutes and flame out then ferment the beer on the cooler side, say 65* or slightly less it will really bring out the citrus flavors from both the hops and the yeast.
What I'd probably do would be to use one bittering hop at 60 and just mix Citra and Amarillo near the end then dry hop with a bit more Amarillo. The dry hopping might sort of blend the Citra grapefruit flavor with the Amarillo for more of a mellow floral citrus flavor. I'm positive that cooler ferment temps and late Citra additions in the boil will give you that really citrusy flavor, just not sure it's the "Lemon" flavor you want.