Definitely go for it. Build it up exactly as you want. My guess is you will grin everytime you ride it or even look at it.
When I retired I built up a new dream road and mtn bike. Bought bare frames. Built the wheels etc. Selected every part and assembled with care and detail. Sold the old bikes to clear out the space for new.
One of the best things I have ever done. No regrets at all. They are both wonderful to ride. Never should have waited so long to do this. Everytime I swing a leg over these machines I just grin.
I did demo bikes for 3+ years on and off to make sure I knew what I wanted and worked for me. Even rented bikes on vacations and events. Got crazy familiar with different geometries, brands, categories, groupsets, ride quality differences, wheels, etc. I did know what I wanted and worked for my needs when it was time to build.
Good luck