First, your 30-year old shower control valve should be replaced to meet current code while you are remodeling. This means it will have the mandated scald-guard technology. This also usually means a single handle control. The two-handle controls usually are thermostatically controlled. It is simpler to use a diverter tub spout, but you could add a handle if you use a separate diverter valve and use a conventional spout.
Trying to match the vanity colors and style might be tough. Another hassle is repair and maintenance on it if you don't know the brand, or it is a 'house' brand. You may never be able to get parts. If you are lucky, that could be a long time, but no guarantees.
Depending on who you ask, you'll get different answers to what's 'best'. Pick a brand that has a decent guarantee and has been around for awhile. Some that come to mind are Delta, Moen, Price-fister (sp?), Grohe. Note, I'm purposely excluding Kohler - too many changes, hard to find parts, long time to get them if you do.