I used the LT1215 and the schematic on page-1 with very good results. The gain I measured was actually greater than the 20 shown in the graph. It's been quite a while since I breadboarded that circuit but I seem to recall the gain was close to 50. But then , my age being what it is , I could be mistaken. In any case, this is an excellent op amp and that amplifier circuit works very well.
It sounds like you could use a tutorial on the Wheatstone Bridge