Just think there's a distinction between doing all your own transport and finding your own spot vs using a transporter to take you to a spot where his clients kill bulls often (both hunts are DIY). Not knocking it, just wanting to make sure you're getting advice aimed at the type of hunt you're looking for. Lots of different transport options depending on your budget and what kind of experience you're looking for.
Western AK has had the best success rates recently (what Vern said). Play around with the ADF&G harvest report tools - you can even sort by transportation type (advanced tools) and see success rates for hunters being flown in if you really want to compare apples to apples. If you're decent enough with data just download the whole moose harvest file for the past couple of years - within 10 minutes you'll see where success rates are high. Then it's just a matter of narrowing down flight options, drainages, dates, etc.