System Image backup

Malwarebytes

SuperAntiSpyware

WinPatrol

A 2-way Firewall (Online Armor, PrivateFirewall, Comodo, Outpost, native Windows FW w/Advanced Security unless you have XP or older)

Firefox w/ various security add-ons (NoScript, AdblockPlus, RequestPolicy, BettterPrivacy, etc.

Sandbox your browser, either with Avast! Pro’s sandbox or something like Sandboxie.

All that together might = overkill, definitely don’t try all at once, but good options there. Definitely better than running two residents AV’s like you were doing.