Recording DAW & VST plug-in for free (or a small price)
As a recording DAW you can try REAPER (http://www.reaper.fm).
Reaper is a professional recoding DAW with anything in it and supports both MAC & PC. It's one of the most powerful tools with free updates (also when you're not a registered user)
It also supports VST - VSTi- DX - DXi - AU - AUi as plug-ins and WAV - MP3 - FLACC and other audio formats as well.
No need to say that I use Reaper for years now and don't want anything else anymore!!!
A good alternative for a VST plug-in is the VSamp (http://www.vsamp.com).
It's free to download and try but registered users can also download many soundfiles (VSamp uses his own extensions) and the half of them sounds good. You can also use the VSamp as stand alone player together with a midi keyboard and make your own soundfiles to use them in the future.
Check it out!