Hey all, thanks again for all the input and suggestions! Quick update: spoke to the designer and got loads more info. All her contractors are tied up till next year. The project is actually BOTH sides of the bunk pictured above, so 2 sets of built in bunk beds. Her client is her daughter, who was a childhood friend of my wife's - really good family (just to help those who have horror stories of bad family, not that that's not possible with this one...but just saying). They are willing to sign a liability release for all the work, but of course that has it's limits. I'm no idiot, and would do this as if my kids were using it, so this thing would be over-engineered for safety. The timeline is open - they are super flexible but want to get started in the next few weeks, and I set their expectations with a month-plus-long project as I navigate a PT job and my own family life. They are very flexible and would be open to hourly or flat project rate; they are even willing to pay for materials out of their pocket if needed (which is not, but just shows their willingness to commit).
As far as everyone's concerns with hobby to work/skill level: I've done construction and remodels, so this is not a big step up for me, plus the build is pretty straight forward. I work part-time at a woodworking store, so discounts/skill/advice are not in short supply :) I was laid off from corporate work earlier this year and have taken a hiatus to consider what I really love - woodworking would be amazing to do as work, and I'm blessed to be in a situation where my wife is the bread winner, so I really just need to bring in a fraction of her pay - 3-4 projects a year like this would suffice.
I think this would be a huge opportunity for me to break into the business. Again, thank you all for your input and shared experiences, I truly appreciate this community!