Ask HN: How to sidestep the patent system?

I'm in the UK and am unlikely to try and sell this outside of EU. I want to create an entertainment gadget that in all probability infringes all kinds of patents (it's pretty much impossible to create anything without doing so - just look at the front page of HN). If all I do is buy of-the-shelf products and put them together with custom software (no software patents in Europe) could I be liable or am I covered because the manufacturers of these products have already dealt with licensing? What if I never sold the unit and billed the owner per month for support and the device would remain mine?