I think it would be worthwhile contacting Cavan Genealogy Centre.
They have quite an amount of Church Records + Tithe Applotment Books,1823 approx,Griffiths Valuation,1857,Hearth Rolls + Flax Growers lists.
For parts of Cavan I know they have remnants of 1821 census.too.
Email is : cavangenealogy[at]eircom.net
Tel.no. : 00353 49 433 1494
Mail address is :Cavan Genealogy Centre,
1st floor,Johnston Central Library,
Farnham St.,Cavan Town,Co.Cavan.
Due to your dates it is the best option
Good Luck