I used a sandwich plate for the oil it's been there for 2 yrs now and i don't have any leaking.  For water temp i used 
hose adaptor and i'm not real happy with it.  It reads about -10°F from the stock sensor and it doesn't react until the t-stat opens.  If your car is stock T into the throttle body hose, you can get all the parts you need from the hardware store for about 10$.  If you want to go big you can drill and tap your water pump housing.  Boost is easy there are 2 nipples on the UIM you can tap into.