Anything can be done, but lugs and carbon stays and sloping top tubes are going to be a challenge. I would guess most people who do lugs aren't going to like that stuff much.
If i were in your position I would up the ante and get a bike that is top drawer, spend a little money. For 2500 you could get almost any frame out there, with paint a variable. By the time you are at 5-6 custom bikes, it's time to ante up for the real cream. Of course, maybe that is what your first 5 bikes were about and now you want to try something wacky...