yup looks lean to me.
Just a heated O2 sensor is enough for a temporary tuning session, remove and use a metal plug when not needed. A regular narrow band is sufficient to get you in the ballpark, and you can read it with a digital multimeter. No need to spend money on a wide band setup. I've been doing this for 20 years with a regular O2 before "Wideband" became a buzz word.
That said, wideband kits have come down in price so much that if you DO decide to get a permanent setup, they are now the way to go.
Note that cheap LED gauges need a voltage regulator to eliminate system voltage fluctuation, or the gauge will lie. Some DIY kits have this included but still get affected by system voltage changes. For kicks I built a couple of those to see if they were any good. In older cars the fluctuation was too great for the electronics to "clean" the voltage sufficiently.
