$1900 is outrageous to regear two axles. My first regearing cost me just over $1300 and my last one was just under $1100... and those prices including Spicer/Superior Axle brand gears, all parts, all labor, taxes, everything.
If you want to just swap in axles from another SE that has 4.10/4.11 gears already, you have to use axles from a 97-06. '95 and older axles are set up for a leaf spring suspension and the job to convert them over to '97 or newer coil spring suspension TJ would be labor intensive, not to mention the need for new brackets... the total cost of which would be more than just regearing your axles would cost.
For only 31" tires, I'm not so sure I'd pay too much to get the 4.10/4.11 ratio that'd be better for that size tire. If you could get a cheap pair of axles from another '97-06 SE that'd be ideal but to spend over $1k to regear your present axles from 3.73 to 4.10 is not something I'd do.