Trying to pin down one rig for bass fishing is like trying to pin down one golf club for golfing. Except golfers have fewer choices to make. That said, there are two rigs that will give you some versatility in many situations. One is a baitcasting rig, 7 ft. Medium-Heavy rod with a Fast tip, 6.4:1 reel spooled with 15 lb. copolymer. With this rig you can throw Texas Rigs, Carolina Rigs, Chatterbaits, Spinnerbaits, Crankbaits, Weightless Senkos, Swimbaits, Frogs, and Jig & Trailers, which are, incidentally, all baits that work when walking the bank. The other rig is a spinning outfit, 6'6" - 7' Medium rod with a Fast tip. Spool the reel with 8-10 lb. P-Line Fluoroclear line. With this rig, you can throw Shaky Heads, Ned Rigs, Neko Rigs, Wacky Rigs, Weightless Flukes, and smaller Jigs. These rigs and baits will allow you to have a number of options when walking the bank, looking for bass, and won't break the bank. A lot of these rigs will work for smallmouth, too. Keep your lure sizes on the smaller end. My biggest producers for bank fishing are small soft plastics and squarebill crankbaits. If there are a lot of weeds along the bank, weightless Texas Rigged Senkos are big producers for me. I even have success fishing 7 or 8 inch finesse worms nose rigged with a weedless wacky hook, twitched along the surface like a small swimming snake.
As far as colors, I keep it simple. Soft plastics: any color as long as it's green. Jigs: Green or Blue/Black. Anything else with a skirt, Chartreuse/White. Crankbaits: Shad colors or chartreuse/black. Good luck to you!