Lovely kitchen in the making but that light fixture for over the table is just too too much. Will you need pendants over the island?

First, use a flashlight to see if there is ductwork, you may need to remove the grill. It is pretty common for people to treat any enclosure like ductwork. If there is no ductwork contact the company and discuss solutions with them. If there is ductwork it likely needs to wrapped with insulation and so the cabinets should be removed and the duct wrapped. If you can't remove the cabinets lining the bottom of the cabinet with ductboard or some rigid foam insulation will help although it is an inelegant solution. If there is no ductwork, you can add ductboard under the cabinets by piecing it in through the vent opening and gluing it to the cabinet. It will be a tedious and annoying job but will improve the problem. ETA: to piece in ductboard measure a piece that fits exactly into your inside cabinet bottom. Shorten it for the toe kick (typically 3.75") then cut it in half. Apply adhesive to each piece and feed them in and adhere them. Use a broom handle to ensure they are adhered. If you want to add sides, cut them to fit (Usually 3" if you are using a 1" ductboard) and adhere them to the sides.

99% of RTA is import junk, with a 0-5 year warranty. including all of those. Industry standard for anytging decent midgrade, like Shiloh, is a lifetime warranty.

By "in frame" do you mean inset doors? As @Verbo wrote, inset doors are a very traditional look because they are constructed like "furniture" as traditional furniture generally has inset doors. They are not higher quality necessarily but they are generally more expensive in the *same* cabinet line. The disadvantage of inset cabinets is that you lose interior storage especially in drawers because the space around the "inset" can't function as interior space. This is less of an issue with upper cabinets with doors since you can place items slightly behind the frame but is an issue with drawers and/or if you have rollouts in lower cabinets with doors. I have a traditional style kitchen which was inspired by Arts & Crafts and I have a mixture of full overlay drawers and inset cabinets in the upper cabinetry which runs into the back of my dining area and so this resembles a traditional buffet although it is built in. For me this represents the best of both worlds as I have functionality where I need it and the aesthetics of inset where it is needed. For me it blends and doesn't look discordant at all. That said, your initial post is confusing - what does the $60,000 quote represent and what is the actual layout and design and style of the kitchen you are contemplating. I don't think anyone can give helpful advice other than inset is traditional in style and is generally more expensive than full overlay. In my experience, I believe full overlay is more expensive than partial overlay but is considered to be a more upscale look.