Congrats on your new baby!
As you've probably figured out, there are a lot of ways to configure these bikes, and that many folks who are willing (or brave enough) to deviate from the DF bike norm to ride recumbent are tinkerers, or at least they aren't afraid to tinker. Take everybody's building advice in, but my recommendation, for now, is to start with a "normal" build--use the stock handlebar, use brifters, use the stock seat pan, etc. Get used to that first, and then let the tinkering begin (you might, for example, really like the stock handlebar). Also, consider taking on only one change at a time, probably in order of greatest need. Eventually you'll move from "I have to swap _________ out soon," to "someday I might try _________."
I suppose this tinkering is the longest part of the learning curve; just don't let the massive knowledge base on this forum overwhelm you. It is a great tool, and it means well.
(I love my brifters too).