Pull Timing Boost

As I continue gathering parts for my turbo build, I was wanting to find a budget way to pull timing under boost. I have seen some information on using an HEI 5 pin module that will pull 10 degrees once grounded. The information I have seen uses a hobb switch at whatever PSI you want it pulled. You can use an electronic mopar distributor and eliminate the mopar box. From what I have found, I am going to use a 5 pin module that was used on a 1978 buick regal turbo.
Just to throw this out there, I saw the NEW Holley 6AL Ultra ignition box at he PRI show and it appears to have a fully programmable timing curve WITH a built in boost reference. All for under $500. 3 timing retard features, 3 rev limit features, all built into the box, no extra modules needed. Looked to me like a great ignition system for a boosted application or even just a street/strip car.