Most Jersey cows can be safely crossed to the regular Angus - not heifers, not the smaller-framed ones. You need a low birthweight bull for those - low-line, Jersey, plenty of little breeds around though not so easily sourced.
Plenty of people crossing Hereford to Jersey too - I wouldn't do it myself, but they get away with it, nice(ish) calves, not too many calving issues.
What mature weight are you looking for?
I've posted this one before - these are new calves from Jersey cows AI'd to Angus. Fine for a small-holder to take through to slaughter but they don't have any true re-sale value.
Why not go for an existing small, dual purpose breed such as the Dexter or Shetland? some breeders have been selecting for a 'beefier' Shetland since their increase in popularity in the UK in recent years.
But you might have trouble selling them on, if that's your goal.
Yellow fat (Jersey) might be penalised at slaughter, might not be. The meat works here just trim the whole lot (fat) off, sell the lean overseas.