I have been to Panama many times and been to a number of places. Here are my best suggestions:
Golden Times - massage - lots of pretty women, they parade them out with numbers for you to pick, prices not bad, very institutional in the massage rooms and usually get in get out
There are a couple of massage places on the main street close to the casino Venetto, some decent choices there. I have cruised the Venetto casino a few times but have never pulled anything from there although I have read that it can be good at times..
I have used the escort agency El Complaciente - lots of photos and accurate. I have had some smoking hot women from this agency, prices not bad compared to Toronto
My all time favourite in Panama city is to go to Habanos cigar bar just across the road from the Marriott. An open air patio at the front chock full of Colombian women looking for a man. Do not bother trying to bring one of them back to the Marriott or other high end hotels as it will be a hassle and they probably will not let her in. I usually rent an apartment in the area when I am in the city - no restrictions on what you can do..
Best of luck, also learn a little Spanish before you go, it will make a world of difference