Nice question this and I have a few suggestions, also hope that others will offer some because my favourite potatoes are much like your description – firm, waxy and yellow.
My favourite at the moment is a second early, Charlotte, also because it is high yielding. But in certain weather conditions the waxiness is reduced. Last year we pulled them (no need to dig when surface grown with a mulch of manure and perhaps other organic matter) on July 2nd, compared to Sharpes Express first earlies ready in eary June. It was an early spring! The Sharpes Express were much nicer in the first half of June than later, I have noticed that first earlies can lose quality and flavour so they are best eaten quickly and just grow a few plants.
I would plant tubers in late March early April and even mid April for second earlies, so they emerge just after last frost, but there is always an element of gamble if you want really early spuds.