Yes, there will be. It's called the iMac 5K, and it's a GPU+CPU+etc attached to a monitor.
Costs less than dell's inferior 5K monitor, too!
Even if you upgrade to a PCI-Ex, or fusion drive, still costs less than the Dell!
It's not uncommon for Dell and Apple to use the same brand/model of panel in question, I've seen that in the past as have some professional reviewers...
Oh, one other thing: There aren't too many "5K panels" in existence. Not hard to deduce that, in all probability, both could very well be the identical panel just with, if anything, different circuitry to process the signal, where Apple's design ends up being the better of the two in producing the output the panel displays.
In some cases, both brands use different models of panel from the same maker and same type (___-IPS, SPVA, TN, whatever...) but in some cases they use both.
So, with that technical primer down, what is the panel brand and its model number that the Dell you referenced used, followed by the one Apple uses? That will help a lot, and that way I and others can make more informed decisions after reading up on specifications and benchmarks (of which there are many) to really know if Dell's equivalent is as pitiful as suggested, though for not it sounds like empty peacock flag banner waving that made more sense when the Jacobites, Visigoths, cavemen, etc, existed.
Much thanks!