Thanks for the tips. I think I have enough info now to order the two shields I need, I'll use the 2 pin data logging shield, but I'm still trying to figure out how many pins a LCD shield takes. I haven't ordered anything yet, but already have an Arduino Uno. I think I'm going to go with the second datalogger @florinc suggested, does anyone has recommendations for an LCD display, I only need text, a 16x2 would work, but 16x4 could be nice too.
If I understand correctly, anything that uses a serial connection is just 1 output pin, and can be grounded to the data ground pin on the Uno (digital pin 14)
I'm also looking for suggestions for a air pressure gauge (barometer, to record the pressure under the hovercraft), air speed of the propulsion fan, and accelerometer. I just want to make sure I don't get duds or parts that are especially difficult to work with.