Any recommendations for a lance build pre nergigente?

Step one: Kill Nergigante.

Step two: Make Nergigante lance. /s

Odawg lance and set :]

Odogaron or Rathian. Both sets are decent.

Edit: to actually take down Nergigante though, I recommend farming a bit to craft an Ingot set. Get a thunder lance and upgrade it to tier 6. I absolutely destroyed nergigante with that setup.

Uragaan: head, arms, and legs... Radobaan waist.... And Bazel chest. This will give you guard 5, and the special skill from the 3 Uragaan parts. Use whatever lance you want. I use Datura pike 3. This without decorations is good enough but with decorations it will shine.