how's it going? there are several options out there you can use. the system i like the most and use is the Holley Annihilator. it's kind of pricey but will work with our ignitions at $300.00. there is another manufacturer that has NICE control units but are more expensive. i think MSD sells some type of control but it might need to be used with one of their systems. HTH....and call me if you have any questions. later...
I have a programmable DPS, digital pressure switch, that I can use that has relay outputs that you can set to 5 different levels.
I only use it for a tuning aid since I can record peak boost with my LED display and I have never been able look at my gauge accurately while driving WOT.
The small relay outputs could trigger a big 12volt relay that could power a solenoid to switch Alky or a double pump etc.
Not sure if they are in production yet but cost was about $280.
Not all that cheap... but a neat tool already engineered and packaged. Easily programmed too.