No using two firewalls is not safe or necessary it will mess up your communication only use one.
Comodo free Firewall is the best there is, bit of a learning curve.
A Firewall stops real time active hackers breaking into your system not for being anonymous on line.
The most anonymous you can get is AdVor
Advanced Onion Router.
This is an Advanced TOR again it has a learning curve.
For advanced VPN use VPN Gate. Made by the University of Tsukuba Japan. 100% free because the Japanese government does not allow these people to make money on this part of their government system.
This is a special type of VPN where every day you get a new random list of servers around the world each day it changes or each time you log on you get a new list too much to explain.
The other VPN that is very powerful is ultrasurf made by to Chinese dissidents in the Silicon Valley to circumvent the great firewall of China if it can get by the Chinese authorities it can get by anything.
The problem with using a regular VPN is that these days web browsers have something in them called Web RTC meaning real-time communication which will divulge your IP address amongst other things regardless if you use a VPN. This is why you need to use a special web browser like the Tor Browser which does everything for you in the background which you may not know about.
As far as saving up for a Mac computer thinking that you're going to be safe those days are over you're wasting your money. The main reason why Mac computers used to be so safe is that they only held 5% market shares in the world Windows had 90% and Linux etc held the rest. It was not worth while for people to try hacking into an Apple device but those days are gone. If you do not believe me simply come through the Yahoo answers security section and you will see how many people with computer malware have Apple computers.
One of The main reason why Windows is vulnerable is because people turn off an important function called UAC especially when installing things like an antivirus which the UAC should be left on when you install your antivirus. This control prevents things from installing into your computer without your permission when people turn this off naturally they get all kinds of viruses secondly if you know what you're doing you can make a Windows computer as secure as you need it to be it's just that most people don't want to take the extra effort and time.
This is How I stay secure and anonymous.
I open ultrasurf VPN using a program called sandboxie when ultrasurf opens it automatically opens Chrome in Incognito mode. Ultrasurf is a special type of VPN which also destroys all web surfing Etc when it closes so together with Chrome incognito mode nothing remains. By opening the web browser in a sandbox that is what keeps my computer totally safe from malicious software entering into it. When the sandbox program closes it initiates a secondary program called eraser which is a wiping program contrary to a program which simply deletes data this completely overrights anything that was left.
This is how I surf the Internet to stay safe and hundred percent anonymous.
Instead of using all the software that you use I just use two Security Programs problem solved the easy way.
If I need extra safety then l use Firefox or Como IceDragon loaded with security add-ons