Those girls almost never get posted here so you are flying a bit blind. I'd say 4-5 of us seem to have wondered this same thing before. We have all come here and made posts, or commented on others looking for the same thing. Your average Colombian who comes to these forums is not going to pay that much money. Your best bet is finding out what you can from the English speaking side (here). I've asked about other forums and they seem to be either focused on other cities, the lower cost market, or both.
Loutron had some super hot ones and some pretty good (non-models) ones. The problem is that it is a house (albeit big house) so there just are not as many girls.
La Isla definitely had model types when I was there. On Thursday night there were over 100 girls. All shapes/sizes/colors/etc. It wasn't ALL models but there were plenty. 320k. I heard Fase 2 is pretty much the same. Some of it depends on the night. I thought Thursday at La Isla was better than Saturday but that may be because I got there earlier on Saturday and Colombians tend to start later.
For 500k you could try
https://escortsfantasia.com/ or
https://modelosalacarta.com/prepagos-en-medellin-escorts-lujo-y-chicas/
I tried repeatedly to let me see head shots before booking and they would not budge. Modelos A La Carta said they would AFTER my first booking but I never got that far on my first trip. Basically you'd have to gamble on the first one and then see the rest after.