Canned and bottled chestnuts are fine for use in recipes - for making liqueur, you really need fresh ones because the flavor is better (at the very least frozen ones)
Marrons (aka Spanish chestnuts) are larger, only have one kernel per burr, are much sweeter and much more easily peeled.
Marrons have a triangle base and a heart shape, they are bigger than other chestnuts and the shell is darker and shiny, tending to reddish in color.
You can probably use frozen (already peeled) marrons for making chestnut liqueur (or in any recipe for that matter) if you do not want to peel them yourself.
Homemade Chestnut Liqueur
2 1/4 cups granulated sugar
1 quart water
1/2 quart cognac or brandy
4.5 pounds peeled marrons
2 bay leaves
4 whole cloves
With a chestnut knife, peel off the outer skins of the chestnuts, without nicking the inner skins, and set them in a large pot of cold water, with the bay leaf and the cloves.
After peeling the chestnuts, put the pot of water up to boil slowly - cook the chestnuts for about 25 minutes.
Remove the chestnuts with a slotted spoon, put them on a plate to cool.
While they are still warm, use a thin bladed knife to remove the inner skins, being careful because the chestnuts will be crumbly.
Mix the sugar and water in a large pot and bring it to a boil (skim foam that comes to surface), let the syrup boil for about 6-8 minutes.
Add the chestnuts to the syrup - simmer them over a very low flame for about 5 minutes - do not stir them.
When everything has cooled, remove the chestnuts with a slotted spoon.
Layer them in the bottom of a wide-mouthed jar.
Return the pot to the fire and bring the syrup back to a boil. Skim the foam a few more times - stir in the cognac or brandy, and let it cool to room temperature.
When the syrup it has cooled, gently pour it over the chestnuts.
Add more cognac/brandy to cover the chestnuts (if needed).
Seal the jar with a lid, and keep it in a cool dark place for at least two weeks.