Hi mate,
I am using a Blitz SBCi Colour (or color if you are american!!!). It is very very good indeed. It has both Speed or RPM mode variable boost control, allowing you to map up to four different boost settings.
This does the job of both the Power Meter and Blitz ID that preceeded it, all in one box.
Very very very good, and does what you want it to extremely efficiently.
BUT, a little on the dear side. Best place to buy is from a recognised jap importer on Ebay. If you do, you can usually get for about 450 quid new!
Hope this helps
JJ