It depends on your level of paranoia and how much money you're storing.
If I had a large number of coins (value > USD$50k), I'd buy a netbook and dedicate it to the sole purpose of signing spends. This safeguards you against virtually any virus or network exploit. Above USD$250k I would invest in some physical security to prevent someone from installing a hardware keylogger in the netbook - any good home safe will be tamper-evident. Above USD$2M I'd look at more extensive physical security, but this won't be a widespread problem at current prices.
I suggest making paper copies of your wallets. A printout of a hexdump of the .7z will do. Keep copies at two or more locations. This safeguards against your wallet getting wiped from multiple sites by a virus.
Your TrueCrypt password is vulnerable to hardware keyloggers, and a hashed (or raw, in some cases) copy is stored in memory while the computer is running, so it's vulnerable to trojans. I would not store your encrypted wallet on that machine. Such an attack isn't too likely as an automated virus, but an attacker specifically targeting you (perhaps because they noticed you have a large wallet and they're looking for ways to decrypt it) would be a problem.
I suggest multi-factor security: encrypt your wallet with a strong, randomly-generated password. Store that password in a text file and encrypt it with your TrueCrypt password, then put it on a USB drive. Only insert this drive when running the LiveCD (or in the netbook). Store copies (paper hexdumps are fine) in a safe deposit box, a friend's house, etc. This creates much stronger hacker-proofing (an attacker needs to get both the physical offline copy of the data AND your TrueCrypt password), while still only making you remember a frequently-used password. If you have a large enough wallet people breaking and entering is a plausible threat, definitely store these copies at a secure offsite location.
If James Bond himself is watching you, I can show you practices that would make the NSA proud, but trust me, it ain't worth it.
Coming back from paranoia-land, I don't know how well-reviewed the client's encryption system is. Is there any reason to store a high-value savings wallet online at all? Keep it on a USB drive and only connect it when necessary. Keep a smaller "checking account" wallet online for daily use.