I like the dual meter method also, analog for O2 and DPR current on CIS-E
cars and digital for everything else.  Analog meters are super cheap at your
local FLAPS.  I personally own a WAVETEK meter with TEMP probe.  Really
useful for measuring tire temps at the autocross track and other stuff like
exhaust header temps and what not.  Another thing that is nice to have in
your meter bag is a set of BOSCH two pin connectors with modified leads and
alligator clips on them so you can "tap in" to your systems for testing.
Check your local junkyard on VWs, Audis and Volvos for these connectors.
Rich Blake