Just get the boost sensing harness from Turbolink and a 3 bar map sensor. Then, plumb together a boost gauge, the map sensor, and a bicycle tire pump, and with the key on, engine not running, with ds running, make your own conversion table of psi versus MAT as displayed by ds. Record the MAT value every 5 psi or so of "boost", or maybe more at high boost (say 0, 5, 10 ,15, 20, 21, 22, 23, 24, 25, 26, 27, 28, and 29 psi). If you want the vacuum portion, replace the tire pump with one of those mity hand vacuum pumps and use a boost gauge that shows vacuum (or just read the vacuum gauge on the mity pump). That will let you log boost, it just won't display it in psi - you will have to use your table to do the conversion but I bet you will get the 20-25 psi portion memorized pretty quickly

. Also, since the MAP sensor is a manifold ABSOLUTE pressure sensor and the boost gauge is referenced to atmospheric pressure, you can see up to maybe plus or minus 0.5 psi difference between your boost gauge and the MAP reading depending on the weather. For fueling, though, the MAP is what you really care about.