I agree with everyone about how great the Omega 8003 is. I have one myself and love it. It's particularly good with veggies, grasses and leafy greens.
It's one weakness, though, is soft juicy fruits, veggies. It's a bit of work with cucumbers for example. Apples work fine as long as their crisp and not soft. I'm guessing lemons would be a problem.
Since it's such a great long lasting juicer at a great price, I'd get it along with a simple manual citrus press. It's not like you'll be juicing 30 lemons at a time. If you were seriously into juicing oranges I'd probaby recommend the Omega VERT instead - though it's quite a bit more money.