I think the 054B would look much like this ship.
The value of having IEP is more closer to ASuW work, due to its quietness, as opposed to AAW and AShP. The latter though is more of the domain of the Type 055 which is why I don't expect the 055 to get IEP soon. However, IEP does not mean its the most power efficient when it comes to propulsion, and for maximum and maintaining speed, destroyers like the Type 055 may retain traditional methods in order to keep up with the carrier. But of course, having said that, the RN Type 45 and the QE class of carriers need to be pointed out are both IEP or hybrid IEP.
Because the role of the Type 054B would be more ASuW, I would rule out using U-VLS or having YJ-18s fitted, like the fan made CGI in the earlier post. The good old VLS from the Type 054A can handily use the Yu-8 ASROCs, and it will fit the eight YJ-83 style canister for more Yu-8s.
Rather than the mini Type 052D CIWS layout, I would go with what is shown with the proposed export frigate, with two Type 1130 amidships, and an 8 cel HJ-10 launcher on top of the hanger. The hanger however still appears to carry only for one helicopter.
The 76mm from the Type 054A is retained, and not the 130mm from the Type 052D.
New AESAs on an integrated mast are a must. The Type 364 Sea Gull C, Type 382 Sea Eagle S/C or Sino-Fregat, Type 345 aka Sino-Orekhs, all have to go as they are growing obsolete even by Chinese standards. Even the Type 366 aka Sino-Mineral ME. The export frigate however seems to still show the Type 366 but the Type 055 is the first large scale Chinese surface combatant not to have this radar. I say large scale as the Type 056 doesn't have it either but its small scale.
Unless the panels are dual band, I would think the panels on top of the proposed export frigate are X-band, and is a variant from the Type 055's top mast. The radar would have to do the job of tracking and illuminating for the HQ-16 missiles in addition to search functions and support for the antiship missiles. Ideally I would have preferred a separate L or S band search radar. Maybe the frigate will retain the Type 364 on the second mast in front of the funnel. Maybe the Type 054B will have a near copy of the Type 055 integrated mast tower. That's can save on costs for both ships.