Warm Audio WA-273 (or WA73 if you only want one channel) or the Golden Age Project PRE-73 DLX MKIII would probably be a nice option to your current pre-amps and both offers excellent value for money. Especially if you can find them used.
Thinking more of a system I would go the 500-series route, get a nice 500 rack and start adding pre amp modules, much cheaper in the long run since you only have to pay for the AC/DC conversion once for every 8 or 10 units. Purple, API, Rupert Neve, WES Audio and more all makes excellent racks, stay away from the cheapest ones, they have a tendency to introduce noise in some of the more sensitive modules due to bad mains transformer shielding. 500 racks are often also available used for good value, they tend to last for 20+ years.