How would something like the Doctor red dot or the J-Point work on one of those SP89 clones?  Can it cowitness with the iron sights, and would the dot be easy enough to see to make it a worthwhile project?

Obviously people like them on other pistols, and as backup sights on rilfes.  My main concern is that I feel that  an Aimpoint or any other  larger red dot would make the package to big and bulky.

Thanks in advance,