I agree with @Cameron Roberts less than 3hrs. You do have to remove the radiator reservoir to lift the engine high enough. Cleaning the old sealant off takes the most time. I used about 5 utility knife blades to clean mine off. Depending how warped it is, if it's not a big leak, probably not very warped. The sealant may just need to be a little heavier there. Just don't go heavy by your oil pickup area(s). Its not the funnest job, but not hard at all.
For a new oil pan you could always source a junkyard one and have a local welder match bung location. Junkyard pan will add an hour of scrubbing inside clean to your time.