Stocking My Own Wedding Bar

Hi, all! My wedding is in a few weeks, and I have a tricky situation related to alcohol. My fiancée’s family is very anti-alcohol (more traditional), whereas my family is very Irish. We want alcohol at our wedding, but figured we either need to have a ticketing system (yuck) or stick to beer and wine (better). We do have a bartender, but the venue does not supply any alcohol.

I suppose my questions are these:

Is there a better approach? If not, we figured ~20-30 bottles of wine for ~150 people. How many cans of beer should we get? (not really a beer drinker) What types of beer should we get? 2-4 different types? Are seltzers a good compromise?

Thanks in advance!