I'll make it simple... Internal frame backpack, single person tent, mummy style sleeping bag.
Im traveling to a lot of different countries for about a year, so does this seem sufficient? I've heard good and bad things about single person tents. Also is a 60L bag the right size for a years worth of traveling? I don't want to go bigger becuase of trying to get into over crowded buses, but I may have to.
Are you certain that bringing the tent/sleeping bag will be worth it? There's lots of big cities where it won't be easy to camp, and most backpackers opt for staying at hostels/guesthouses everywhere (renting tents/sleeping bags for those few occasions where they go on overnight hikes). It'll save you a whole lot of weight and space...
A sleeping bag is one of those things I think is important to have on you, although the tent is really just excess. I may opt for no tent and just rely on hostels and whatnot. Although getting in a country and try to scramble for a hostel can be a real pain in the ass, and having a tent to pitch is a convenience and a money saver. It's just a matter of finding out where I can camp.
Most hostels in most countries don't allow the use of sleeping bags, as they spread bedbugs. I'm recommending against bringing one based on travelling with one for 2+ years myself, during which times I only used it for two camping trips. (Do bring sleeping bag liner, though!)
I always do my research on accommodation before setting off to a new city, and book it ahead so that when I arrive I only have to find my way there. Definitely don't think I'd like the stress of trying to find a place when I'd be all tired right after getting off the plane.
Sounds good, except then I pretty much have to plan my entire trip ahead of time. When you say to book ahead are you talking about booking every accommodation well ahead of time? Or just booking a few days before? Or maybe a week before?
A day to a week in advance, depending on country/time of the year (for example, the south island of New Zealand requires a week in advance during its high season of late December - March; Sydney at New Year's would require six months in advance, European capitals from June - August would benefit from a month if you want someplace decent).
If you have a solid idea of where you want to travel, it's always worth booking ahead, though. Many cities have events and festivals you know nothing about which can cause all accommodation to be full, and so it would be good to know about that before arriving, when you can still change your plans. If your plans might change after having booked, you can cancel without any cost up to 48 hours before the date you booked. (At least in hostels if you called them directly to book. Not as easy when going through an online booking system, and had to put down a deposit, as those usually aren't refundable.)