Cubitac Cabinetry has some very poor reviews on Google if you will search there and sort by lowest to highest ratings. Those types of comments and the number of them in the low category aren't what I like to see with a cabinetry brand I would recommend. Do a similar search for Google ratings on 21st Century, and you'll see quality and service rankings in a similar pattern.

Shiloh is actually considered a budget cabinetry range. Shiloh offers several different lines that vary in price. Some people have had poor experience with Shiloh, but many people have had truly great experiences with them. It's a brand I would recommend getting a quote from, and like any company, searching for current reviews. There are at least half a dozen threads here at Houzz that go into depth with Shiloh quality and customer service reviews, so I would look those up if you want to head that direction. I've done a lot of research on Shiloh and decided not to get a quote because I wanted top-notch cabinetry with a flawless customer service record. Shiloh isn't there at the tippy top, but they are worth considering because the value they offer for the price is very good.

Honestly, it sounds like IKEA cabinets would be a better value for you if you want to slash the budget than the first two. It sounds like you have a lot of cabinetry or special feature requests for a Shiloh quote to come in at that price.