Whatever system you choose you will need a conversion class (or a foundation class I cannot tell from your profile whether you are trained or not) to be able to make it look and feel easy, not to mention loads of practice.
And for the non yellowing part (and ease), ensure you buy top-quality products eg. Ez-flow, CND, Oddysey, Nsi, young nails and likewise, but most of those (maybe all) you won't be able to purchase without training of some kind...