I'd have a recommendation for Waco, but not for your area. I had my 2 side by side tanks pumped 2 years ago, it was $300.
The pump operator won't have any trouble locating your tank, it'll be close to the house. They'll use a metal rod to probe the ground until they hit the tank, they'll also be able to tell the lid from the rest of the tank. If you have a plumbing clean out, the tank will be nearby. Also, the grass is usually much nicer close to the tank and the leech line.