Yes the Island Venture has the Moon Pool and foundation to fit a Vertical Lay Tower. She may even have Carousel(s) below deck, or be prepared to fit them on deck, but none installed. The same goes for Well Intervention Tower and equipment.
I don't know if there are any of this equipment available, or being manufactured, in the US. Obviously the equipment can be shipped to the GoM, or wherever, on a HLV and be installed there, but most appears to get such equipment installed in Rotterdam, which is a fairly lengthy operation.
If ECO is aiming at such work it seems to me that it would make sense to install the equipment before leaving Europe. The vessel has been idle at the building yard for long enough time to get it manufactured and ready.
Any insider information on what is actually planned for the Island Venture when she get there??