For sure you can use this guide. Just find big or few smaller(you need a lot of locations?) companies who offer vps + additional IPs. Speak with support and say what exactly you need. 100% you will get good discount. Just need speak with them + setup. One time job
Have a look here _http://www.webhostingtalk.com
99% that proxy providers have tons of servers + ips and they use smth similar to this guide. It's pretty easy to make auto setup if you have servers.... And they sell one IP to me, second to you, third to some one else from one server. So for us looks that we have "random" IPs
It looks hard first time, but it's only first time. Always feel free to ask any questions.