I'd go for saddle if you're uncomfortable with your current one. Even wearing the nicest shorts and on a bike with the sweetest tires on, I don't wanna ride much on the wrong saddle.
I can ride 35 miles in Levis at a mellow pace on the right saddle. I usually roll out in Wrangler shorts. Not denim shorts, a light chino type fabric. Shorts don't really matter unless you have problems. I don't have problems personally because I ride 30-40 minutes a day in non-cycling shorts or pants, so I've built up a resistance to those kinds of problems. If I'm heading out for 50 miles or more, I usually get my cheap Canari bike shorts on, however.
I typically ride crappy tires like Michelin Dynamics, but do occasionally spoil myself with better tires. Dynamics are fine if you don't wanna take really fast turns. I don't think I'll be getting any GP 4000s anytime soon unless I can find them for $25. I've decided that $15 is too little to spend on a tire, but over $25 is too much. Tires really don't make you that much faster, they just feel better, especially in the curves.