what do you consider "your vitals"
im a VDO fan. my dad is a marine elctrician and has been buying their gear for 15yrs+
i have a VDO water temp guage which has served me well
it cost me around $40 for the guage, and about $30 for the sender.
i will soon get a oil pressure gauge, but the senders for oil pressure are VERY expensive (arund 80-90$ for the sender) and the guage is around $40 or so (last time i checked)
thast about all you really need i reckon, all the rest are a bit wank factorish.
please dont spent 100's and 100's of dollars on brand name hks/omori (whatever it is)
VOD is easy to get through repco