For those on a limited budget the Amiko Alien 2 is an option, dual boot so it will run their own Spark software or E2, triple tuner and I see that the sponsor is selling a grade A box at £149.

I'll be open about the main downside of the Alien 2, it uses a different processor from the other E2 boxes mentioned, so the choice and maturity of the E2 image is less, go into it with your eyes open and you'll be happy. The box is certainly quick, and well known for excellent picture quality, better than boxes that are more than double the price by some accounts I've seen.