Eureka Arsenal does make a nice Model 1889.
The idea of first deciding on what you're portraying, and then concentrating on that alone, will save you quite a bit of money during your initial outfitting.
Following that - remember that the Army had a most generous 'wear-out period', so you can add later-issued articles of equipment and clothing slowly, and still be well within Army Regulations of the times.
During the period, the only ones outfitted with the newest gear would've been those serving on the East Coast, or at higher-level units where new things would be shipped.
The field units weren't getting anything brand-new.
Vaya,
Scouts Out!