IMO, not really.... at least not such that you could attain the same level of performance.
I'm not certain, but suspect that the boats you saw are carbon/nomex, which means prepreg construction (big autoclave). To home build, you'd have to go with heavier carbon/foam and wet layup or infusion.
Not trying to just be a pessimist, but I had access to a set of molds for a 20' carbon cat and after looking at the cost of materials decided that it didn't make sense.
Australian Nacra Nationals done and dusted for the year, I’ll post a proper write up but just a quick note for now. 40 Nacra’s competed including 19 x Nacra 5.8’s, 118 people at the presentation dinner. Next Aussie Nacra Nationals is at Hervey Bay Queensland and that fleet will be huge, we got 19 X 5.8’s to South Aus so we should see about 40 x 5.8’s in Hervey Bay plus all the other boats. I’ll do the proper write up soon but start booking your accommodation for Hervey Bay