Bigger than what? I take "tour my ass off" to mean riding more than carrying the kitchen sink.

.02 is to start with a set of front panniers, front low rider rack and rear rack then learn to pack and tour with that capacity. If you need more capacity over time get another set of panniers, front or rear. Starting off with the whole shebang of large rear panniers, front panniers, handlebar bag, rack bag, simply commits you to carrying a lot more stuff than you may actually need to ride and enjoy the trip.

It also gives you the opportunity to try different configurations. Front panniers on lowriders with load on top of rear rack holding bed/tent gear. Or smaller front panniers on the rear rack with same load on top, or lighter load with everything in the panniers.

If you need just a little more room and you have a 56cm+ sized frame check out Revelate Designs medium Tangle frame bag. It's a good replacement for the ubiquitous seat bags folks put tubes and stuff in. When you start piling stuff on the rear rack a seat bag gets in the way of moving things as far forward as possible.
the medium is a good size for holding a range of stuff besides tubes and tools.

I'm not a fan of handlebar bags that cantilever weight high and forward but a lot of folks like them.

You don't have to go top dollar with Tubus and Ortlieb, there are many other products that are perfectly serviceable for half the price. Knowing how to secure things properly, rack to bike, bags to rack, matters a lot more than tossing down a pile of cash for a pile of stuff. For top dollar a Tubus Tara lowrider, Logo rear rack and Ortlieb Sport Packer Plus would make a good starter set up.