we just used a sling seat (like the one in PPs link but just the seat) and put it in the big bath tub until she could sit up. Never needed an infant bath!
I had one once, it wasn't bad, but to be honest, four of my dks were off the charts, I never used baby baths. I used a hand towel and only put in one inch or less of water. It really was just a in and out until they were big enough to play and sit.