The individual strain gauges are probably beyond most of the experimenters – and they are pretty pricey compared to simply buying a completed load cell with a full bridge (4 strain gauges). But if you want - you can find the bare strain gauges on amazon for $3 to $6 1/4 bridge instead of the $60+ from digikey.
Sparkfun does have a load cell / measuring shield called “Openscale” available – and it works with the load cells that Sparkfun and the other “maker like suppliers” offer up.