Hi,
The Cisco ISR 1900, 2900 and 3900 Series adopt the Universal IOS image model so you have enable license for the features.
According to the features specififed above you will need: IP base,Data and Security license.
As far stability is concern the latest IOS for the device is 151-4.M1 which contain maximum number of bug fixes and is most relaible.
Here is the link to download IOS for the device:
http://www.cisco.com/cisco/software/release.html?mdfid=282774228&flowid=7442&softwareid=280805680&release=15.1.4M1&rellifecycle=ED&relind=AVAILABLE&reltype=latest
To know which license you should enable on the device for the features you can refer to the document:
http://www.cisco.com/en/US/prod/collateral/routers/ps10616/white_paper_c11_556985_ps10537_Products_White_Paper.html#wp9000809
Hope this help:)
Regards,
Sonal