I have a bride that would like at least one tier of her cake to be tres leches, I haven't made this yet and I was wondering what everyones opinion was on using it for a wedding cake.

Also she mentioned that she had had this cake before and the person that made it had substituted a milk based alcohol like baileys or kahlua for one of the milks, Has anyone tried this and is there a recipe out there for this?

Thanks in advance!

There are a couple of recipes on this site, I haven't tried any of them but it is probably a good place to start. FYI, this is a very 'spongy' (is that a word) wet cake (and has to be kept in the fridge if you read the recipe) so take that into consideration when you are planning your tiers. Good luck

and also tres leches cakes are very delicate I personally wouldn't stack them unless it was the top tier (no weight on it) but them they also sometimes leak if it's a "cascade type setup then i would think it's ok but if they are stacked i would shy away from it.
As for the other question. traditionally tresleches is flavored with liquors like gran marnier or drambui even ammeretto would be good. remember that you are boiling the 3 milks mix anyways and the alcohol will evaporate out.