My recommendations:

Hotel: In my opinion, Starwood has the best reward program. They are fantastic about upgrading platinum's to suites, no blackout dates and many hotels are available for 3000 - 4000 points. (You'll probalby earn that during 2 weeks travel using the Starwood Amex credit card). Some examples at that redemption rate include the Royal Orchid Sheraton in Bangkok (Conde Nast Gold list for 5 years), Le Meridien Angkor (closest hotel to Angkor Wat, Cambodia), many Four points (saved lots of money in Munich during Germany 2006 World Cup)

If you are traveling to cities with Sheraton, Westin, W, etc., I'd highly recommend Starwood.

If you decide to do the Starwood option, consider the United Ameniti program (search the United forum). Promotions offer something like 25K miles for $295 and you'll get Starwood gold status for accelerated point earning and room upgrades

Airline: If you are going to travel more than 200,000 miles per year, I highly recommended diversifying across 2 airlines to reach top status on each. You'll then have flexibility to choose by schedule when needed, have international upgrades on both airlines, have more options when you want to redeem miles, etc. I made the mistake of flying 240K miles on 1 airline during 1 year and regretted not getting top tier benefits on 2 airlines.

Credit card: Starwood Amex as suggested by others

Good luck adjusting to the constant travel.