Information on the contents of Poland's National Archives are available in two forms. You can get it from a somewhat hard-to-find book or online in the state archives database.
Below are the holdings for a few select Bukowsko Triangle villages which should give you an idea of what the archives hold. As is happens, all of the books mentioned below are in the Przemyśl archive. Other books are available for many Bukowsko Triangle villages in Bukowsko's archive.
In the top field enter the name of the village you're after. For instance, I can look for all of the records for Prusiek. You can search a little more broadly by leaving the first field blank and entering a gmina name in the second search field like Bukowsko or Sanok. If your village or gmina name contains characters specific to the Polish alphabet, just use its English cousin. For instance, a search for "dlugie" or "długie" turns up the same records.
I use English/Polish abbreviations for births/urodzenia (B/U), marriages/małżeństwa (M/M) and deaths/zgony (D/Z).
Kamienne (Greek Catholic):
B/U: 1784 - 1847
M/M: 1784 - 1799, 1801, 1803 - 1810, 1813, 1816, 1818 - 1819, 1821 - 1822, 1829 - 1840
D/Z: 1784 - 1840
Morochów (Greek Catholic):
B/U: 1791 - 1829, 1831 - 1835, 1837 - 1845
M/M: 1791 - 1793, 1795 - 1800, 1821 - 1830, 1833 - 1835, 1837 - 1845
D/Z: 1791 - 1810, 1821 - 1830, 1837 - 1845
Prusiek (Greek Catholic):
BMD/UMZ: 1835 - 1842
Sękowa Wola (Greek Catholic): (also known as Wola Sękowa)
BMD/UMZ: 1814 - 1843, 1845 - 1851, 1913
Wolica (Greek Catholic):
B/U: 1835 -1842
M/M: 1835 - 1837, 1839 - 1842
D/Z: 1835 -1842
Belłchowka, Ratnawice, Nagórzany, Nowotaniec, Zboiska and Dudyńce:
No entries (sorry!)
All of the information available for a given village is repeated on this page in entirety. In other words, if you're after (for instance) Roman Catholic records for Prusiek, it seems that you're out of luck, at least as far as the national archives are concerned.
The full title of the book is (deep breath) Naczelna Dyrekcja
Archiwów Państwowych Centralny Osrodek Informacji Archiwalnej with the
subtitle Księgi metrykalne i stana cywilnego (w archiwach
państorowych w Polsce). It was published in Warsaw in 2000 and has two ISBN numbers:
83-86643-53-6 (NDAP)
83-7181-160-8 (DiG)
Only 500 copies were printed, so if you come across one, kill if you must but grab that book!