Let's just keep this all in 1 thread, to make it easier to read.
AFAIK the avast! Pro doesn't have any antispyware included. Don't just leap in & buy something when you have the chance to test a free version first
Some things just don't work well for some people...for instance I just can't run avast! successfully. But I can run others. Go for the freebie first, if you're happy with that then upgrade to a paid version if you want to.
It's not so hard to have separate AV & antispyware, I wouldn't be without Spybot & Ad-Aware. Give things a try, find out how they work for you.