Eustacia is a faux-mobius (“fauxbius”) wrap, and is appropriate for all knitting levels.

To substitute yarn:
Staccato (discontinued) was a fingering weight yarn, and can be substituted with another fingering weight yarn, held together with two strands Silk Cloud (as in the original).

Another option is to use a single strand of worsted weight yarn (omitting the need to hold multiple strands of yarn together; you would not use the Silk Cloud in this case).

Basically, as long as you get a fabric with the look and drape you like, you should be good!

In either case (substituting with another fingering weight yarn or with a worsted weight yarn) you will need approximately 950 yards of that yarn.