Internet Banking on Ubuntu

I am considering using Ubuntu solely for internet banking purposes, as security experts do not recommend using Windows for internet banking and recommend to use a Linux distribution, specifically Ubuntu, while using internet banking facility. Therefore I want a completely sandboxed environment where I can perform internet banking without any reservations.

I use Windows as my primary operating system (OS) and perform activities like daily internet browsing on Firefox or Chrome, routine office work on Microsoft Office, playing games etc. I do not intend to discontinue the use of Windows; as mentioned before, I want to use Ubuntu just for internet banking (transferring funds, paying utility bills, etc.) and rest of the working will be performed on the Windows PC i.e. I want to use both OSs on the same machine.

I can use Ubuntu for the intended purpose, in the following three ways:
1. Using a live CD
2. Installing Ubuntu in a USB
3. Installing Ubuntu alongside Windows using ‘Wubi’.

I fear that if I install Ubuntu in a USB or in my hard disk alongside Windows, then Ubuntu will not remain isolated since viruses and other malicious programs in Windows and other hard disk partitions can infect Ubuntu and may result in security issues. Also, a malicious program may be installed without my express consent. Therefore, the only option that seems to be secure is only to use Ubuntu using a live CD since this is read-only and nothing can get installed on the disk and any information, that is stored in computer while browsing the internet, is ‘un-loaded’ from the memory as the computer is restarted.

I wish to have your expert opinion about which of the above options provide the optimum security. With your suggestions for using the best way of using Ubuntu, please also answer the following queries:
i. Is any antivirus e.g. avast or Firewall necessary to further enhance security?
ii. Among Firefox and Chrome, which internet browser is best to use?
iii. Is it safe to allow the internet browser to remember passwords in the browser’s password manager (in case of last two options above)?
iv. Is it safe to store passwords in password management software e.g. Keepass?
v. Any other suggestion on using internet banking on Ubuntu.

I would be grateful if you answer the above queries and provide me with the most secure way to use Ubuntu.

Regards,

Nadeem uz Zaman