Looking for Goat Meat
The La Fiesta on 183 Ohlen had it the last time I went in. In fact, had the goat head staring right at me through the glass.
Goat is something you either like/hate (very oily). I'd figure about 1/4 - 1/3 pound per person and do a "roast" cabrito with lots of tomitillos, chili and beer. Think carne asada only with goat.
World Food Halal Market at Lamar and Rutland (NW Corner) and Madina Halal Market just south of Rundberg on Lamar (SW corner). The latter store has changed hands a few times but it should still be a halal market.
Sorry - no suggestions on cuts since I don't know how you plan on serving it, to who, and with what else.
I bought some goat loin chops at Salt and Time a couple of weeks ago. They were, IMO, very expensive, about on the order of Central Market loin lamb chops or maybe a bit more. For that reason, they are not going to be a staple on my table. That said, I left them with a little red wine, EVOO, garlic and rosemary for a while and grilled them. They were very good eating. It has been a while since I had cabrito. If tasted blind I would have known that it was not beef or lamb but it might have taken a while to decide on goat. For the number of people you mentioned, I would go for a whole young goat and grill/roast it over wood/charcoal.