Multi layered security suggestions...

Sandboxie and that`s all you would need to add to your setup.

 

since you already have firewall + hips.

you should add confidence in current software, and try to add as little as possible.

unless you have wilders syndrome , add everything and anything you want, go crazy and have fun

 

I was thinking Sandboxie immediately, until hearing that Outpost had an adequate sandboxing module included in it. That being the case I agree with the people that said EMET. It is a different type/layer of security, and that's what you're looking for here. All the other stuff mentioned seems to be some type of overlap with what you already have in Outpost, which you say you don't want.

Perhaps also consider Shadow Defender. So my answer = EMET + Shadow Defender. Then you've got yourself some nice layers in place.

 

I would have to say AppGuard because it covers a few areas that Outpost may not. Also, you have to be careful about using some applications together that may use the same hooking method. They can conflict. I would also recommend a traditional AV with your setup; preferably one light on resources with a good detection record over the past 2 years with independent testing. Any AV can perform well, or bad any given month. In my opinion you should look for consistency over a two year period, or more.