Just stating large numbers of analog I/O points doesn't tell me anything about your application, so I really can't say whether a MicroLogix is appropriate for it or not.
In general, I would not use a MicroLogix controller for a high-analog-I/O-count system.
The largest CPU in the MicroLogix family is the MicroLogix 1500 model 1764-LRP, which can run 16 expansion modules, and the highest density Analog Input modules for the 1769 platform are 8-channel modules. That gives you 128 analog inputs, well short of your goal.
Selecting a controller or I/O system requires more thought than the number of I/O channels. You need to consider isolation, and accuracy, and speed, and communications.
The Rockwell Automation "
Integrated Architecture Builder" software can help you compare various controller and I/O platforms quickly.
Of course, IAB is aimed at ControlLogix and CompactLogix because those are the modern controller platforms. But it also provides estimators for distributed I/O platforms and for SLC and MicroLogix controllers.
That might be a good tool for you to run on your own, in conjunction with well-considered, thoughtful questions here on the PLCTalk.net Forum.