Hey, Barry1976 welcome to the forum. Firewall many use Online Armor or Comodo w/o the av.
For anti-spyware I use MalwareBytes Pro. MBAM Free is also good http://filehippo.com/download_malwarebytes_anti_malware/
and Super Anti-spyware Free http://filehippo.com/download_superantispyware/
Neither one will conflict with avast. I also use WinUtilities Free http://download.cnet.com/WinUtilities-Free-Edition/3000-18512_4-75021441.html

I’m sure others will also give you their suggestions. Whatever you decide I wish you the best. :slight_smile: