2048x1536 was a common maximum resolution on high-end CRTs 10 years or more ago, but hard to find on modern LCDs. If you really want that as the monitor resolution, there are a few medical diagnostic monitors that have it: http://pcpartpicker.com/parts/monitor/#r=204801536
In consumer-priced 24 inch monitors, you won't find higher than 1920x1200 resolution. If you're willing to go up to 30-inch diagonal, you could get a 2560x1600 monitor and run 2048x1536 on it with black borders.
there are several 2560x1440 monitors @ 27", especially from korean brands. They all use LG panels - brands to look for are yamakasi, acheiva, crossover and potalion. There are a few others. If you live near a microcenter, they have their own - the auria. There is also a domestically produce line fro overlord computers. All these monitors will average $4-500 for a 60hz model. If you want a 120 model, it's around $700 form overlord, or $850 from 120hz.net to get your hands on a 120hz yamakasi catleap. If you're the tinkering type, you could try to find one of the 60hz monitors for cheap on craigslist, then get the 120hz PCB from overlord (the pcb will fit yamakasi's, achieva's, and overlords own. will *not* fit crossovers. unsure about potalion and auria.)