If you are familiar with Reaper, then Ardour would probably be a better replacement than Audacity. Both Reaper and Ardour are “real-time DAW” applications, whereas Audacity is a WYSIWYG audio editor. Ardour ‘should’ be pretty stable so long as your hardware is fully supported (particularly important is that your sound card is fully supported, and this applies equally to running Audacity).
For running Ardour, it is highly recommended that you use Jack audio system. Setting up Jack can be a pain, but well worth the time and effort once it is set up. If you are intending to mostly use your computer for media production, there are benefits to using one of the Linux distributions that are optimized for media production such as AV Linux, KX Studio, Ubuntu Studio …
Note that a Linux based audio studio is a ‘minority interest’, especially in comparison with Windows and Mac. Consequently you will quickly discover that there are few big companies to set things up for you - you can’t just hand over a fistful of dollars in exchange for a fully configured Logic / Sonar / Cubase system. On the other hand, if you like to roll your sleeves up and spend time finding and configuring the pieces of your e-studio yourself, then Linux can provide a hugely powerful and flexible set of tools which can be configured the way that “you” want.
To answer your question directly, Freeverb3 includes convolution reverb (uses impulse files to generate reverb via convolution). Unfortunately ready made Freeverb3 plug-ins are quite rare, but I read that one is included in KX Studio.
As a more general point, Calf Studio Gear provides an excellent set of high quality plug-ins, but unfortunately the current versions are not yet supported by Audacity (they work fine in Ardour).
I am really liking the Linux setup, some of the software is great. I think i’m just looking for one program fits all; even though i never had this on windows either. I’m not looking for anything pro; more like bedroom musician. I will continue as I were but replace reaper with ardour. Ardour seems to be everything I want.
I do really like the simplicity of audacity and some of the tools like spectrum analysis have really helped.