Don't be talked into back skins, they're just a waste of money. Maybe do 1-2 shoulder mounts out of your five animals? I will agree with most here that African taxidermy is rather ordinary and there is no real cost savings anymore.
Shipping/customs brokers are crooks IMHO and even though I was quoted a price, it was much more. What am I going to do drive to NY and yell at them in their office? You may get reasonable quotes on taxidermy done in Africa, but when you add all the fees.....transport/customs/storage you'd have probably been better off having them done in the US.
Another thing I've learned is many African outfitters don't have very good field staff to immediately care for your stuff. Many use old salt and your capes can really suffer.
I've come to the conclusion to do more euros, take high resolution photos.....that can be reprinted on canvas, and call it good. After enjoying my shoulder mounts for 20 years and downsizing, I sold 75% of my heads. Obviously I didn't recoup the costs of mounting them, but I made more room and probably got 35% of original prices.
I did a euro on my cape buffalo on a beautiful piece of wood and it was a smart choice. It saved space and money and has it's own unique beauty.