Vacuum Advance / Boost Retard unit

Is there anything out there like the corvair vac/boost can that might be easy to retrofit to a standard dizzy, I've been doing a little research and have found someone that makes one for the turbo corvair, but I'm not spending $125 to hack it up and try it...

I'd like to not have to replace the ignition and buy a boost timing module just to retard the timing a couple of degrees...

Just thinkin out loud, ALL thoughts welcome..well almost ;) I don't want ppl to tell me to suck it up and buy the MSD unit...that's the fallback plan, but I'm still saving...