I have been having trouble choosing an appropriate op amp package that meets the criteria stated in the tittle of this thread. Most of the op amps recommended in the medical applications section of this website are SO packages and too small to use in prototyping breadboard. Any suggestions or advice on choosing a particular model ? The functions required are for the Right leg driver and filtering of the ECG. I already have an instrumentation amplifier
A right leg drive amplifier is purposely used for common-mode bias and for noise cancellation especially the 50/60Hz. A high CMRR and and low noise amplifier would suit this application. OP90 and OP193, which Oliver had suggested, are good choices since both are micropower amps, high CMRR and have low voltage noise.
You can also try OP97 and OP07 which have a noise voltage of more or less 0.5uVp-p and have higher typical CMRR of more or less 120dB. These two are also micropower amps but is more or less 400uA supply current. These are offered in your required package which is DIP and also in SOIC which cost cheaper.
If you are currently using SOIC part, you may want to use an SOIC to DIP adapters for breadboarding purposes. You may want to look at this link.
Hope this helps.