Hey, I love chant too! To help you with your first query:
I’m not sure what your background is listening to chant, but there was a famous CD issued in the 90s by the Benedictine Monks of Santo Domingo de Silos simply called “Chant” that is great, if you don’t already have it. Anything by them is very nice. I also suggest the monks of Solesmes, who have a large discography – Solesmes is where a lot of chant scholarship took place in the last 100 years or so, and they really know what they’re doing. Here’s a link for the Solesmes monks:
I know you said you weren’t as interested in female voices, but nonetheless I strongly recommend checking out the group Sequentia as well (they’re a mixed ensemble, and they have some recordings that are single-gender too), especially their recordings of Hildegard of Bingen and one called “Chant Wars.” Beautiful stuff!
Most of the above is Gregorian chant, which is hopefully what you’re looking for (there are other types of chant too, but not as much of it is recorded). Also, forgive me for mentioning this if there is no reason to, but some people I’ve talked to confuse chant with medieval music in general – if what you’re actually looking for is medieval polyphony, I can help too!