This topic has been discussed, many times, before. It is a good idea, until you start to analyze what needs to happen to actually do it (and, for now, we can ignore the laptop problem).
First, somebody has to put out some cash to buy a few different combinations of hardware (the case is the least of the problems) and determine what works best. Then, they need to determine if the devices are still available, substitute something else for those devices that are no longer available, test again (repeat as necessary), and then they need to put out enough to purchase parts for about 1000 machines (to get quantity discounts). Okay, after a month, or so, you get a truck load of parts, that need to be assembled, and tested. Then, you can offer them to prospective buyers, and each one will want different features. If you are lucky, you might sell 75% of them in the first year. By then, all of the parts will be obsolete, so there would be an expectation that the price will drop. You also need to determine if you will sell them with OS/2 (ArcaOS) pre-installed, or if you will just sell the hardware. Then comes the problem of whether you include an option for windows, or Linux. Do you pre-configure the HDD, or let a user do that? And so on. You would probably also run into problems trying to ship across international borders, and methods to get paid.
Laptops, of course, come as they are. you cannot just mix, and match, parts.
Keeping a database of current hardware (which is usually 6 months out of date, in a world where there is a 3 month turn around on availability) is probably the best that can be done. The advantage is, that by the time somebody says that a specific device actually works, it will likely be on the clearance shelves, at a discount (if you can find it), but the replacement part will still be cheaper. Then, there is the problem where a manufacturer changes the specs on a device, part way through a production run. The 1000 devices that you order may not work, while the one that you tested did work (this problem also exists while trying to maintain a database).
Good idea? You bet, Will it ever happen? Not very likely.