I bought and overhauled a first-run O-360-A1A in '98-'99 for my RV-6, when you could still find an O-360 core. A new O-360 from Van's was about 21K back then and I had a total of 12K in this one, and I had all new parts in the cylinder top ends, new pistons, all new accessories and many other new parts. It's been great for 1550 hours now except for a cracked cylinder at 1450 hours. Bought a set of used cylinders that had 150 hours on a good overhaul by a great shop, had that shop check 'em again, and installed them for about 2K.
Beyond any cost savings, you are learning a lot that will serve you well in the future. I had Divco do my case, too and they were super, and I've done some business with Aircraft Specialties and I would recommend them, too.