LZCS - 405nm 100mW Focusable Violet Laser Pointer

I was basically wondering two things.
Would I be able to swap lenses out on this laser? What would be a good starting point?

If not, what are some good external lens solutions?

You might want to get a higher power laser before buying lenses. The G1-G2s are expensive, and the extra power you'd get would not be worth the price. You'd only get ~30mW extra at best. For close to the cost of the lens you can get a 500mW 405nm diode.

Yeah, those G1/G2 lenses provide about a 30% increase in transmitted power over the regular glass/acrylic lenses. So that means you should do a cost calculation to determine if you could get a 30% more powerful laser for less than the $50 or so for the lens. Usually you can, especially at 100mW power levels.