Hi, I hold a Nepali passport and am a US permanent resident. I plan to travel to Nepal en route Hong Kong via Cathay departing LA. I believe I require a visa even though in transit less than 24 hours each way. What type of visa should I apply for - Transit or Tourist? Any idea as to how long the procedure takes to obtain a visa here in the US? Can I use a visa assistance company to help me out?

Any help is much appreciated. Thank you!