I plan on working with Finn Verdonk.
Netwar (ISO tnl), the language of the Lenakel, is an agglutinative Austronesian language spoken on Tanna island in the Republic of Vanuatu. It was spoken by 11,500 speakers in 2001, and uses the Latin alphabet for writing. It seems relatively easy to find texts for; I found [a grammar guide] relatively quickly.
Pontic Greek (ISO pnt) is a variety of Modern Greek spoken in Greece, Turkey, Central Asia, and Russia. It has a total of about 778,000 speakers in total, using the Latin alphabet in Turkey, the Greek alphabet in Greece, and Cyrillic in Russia. With just a cursory search, I couldn't find many texts for it, but I don't imagine it being extremely difficult with further searching.
Zenzontepec Chatino (ISO czn) is a variety of Chatino spoken in Sola de Vega. It is an inflected tonal language which uses the Latin script. There are 52,100 speakers of Chatino as a whole, but only 8,500 native speakers of Zenzontepec Chatino as of 2000. I didn't find any texts in the language, but I did find a large grammar guide, though I couldn't see a great many examples within it with only a cursory skim.