Regardless if you chose IP-057 or IP-256, or even some other model, I highly recommend the following options when people order their frame:
Bottom bracket --> My recommendation is to choose BSA if possible.
BSA has proven reliability, large bearing surfaces, works with most all crank options, no press tools required, far fewer instances of creaking or bearing problems.
UD/3K/12k carbon weave --> UD is said to be the lightest but is very plain looking (no weave), 3k is the typical, classic, tight carbon weave pattern and is what I like, 12k is a wide weave. See picture below:
Matte/Glossy Finish: This is personal preference, both look great.
Don't forget, many of the Chinese vendors will also paint your frame a custom color/pattern for around $75 extra. Rather than getting a plain black frame, consider a custom paint job, they have some great colors available.