Start only with one koi. They are bottom rooters and mudders. When larger that 24" they can easily cause pond turbidity. Bass will likely eat all gold fish you stock with is really a good thing. If you live at the pond you don't need an automatic feeder for a 1/4 ac pond. Hand feeding 2-3 times a week with good quality food does help improve the fishery for BG.
To check on the fishery balance do some angling with a small hook & live bait. Then keep records of what and how big of everything you catch per total hours of fishing. Report back and we can provide more information. Close up clear pictures of fish you are not sure of will get you more specific information and management ideas. In the mean time scan through the Q&A Common Pond Question archives to learn more about pond balance. You can also search this forum of pond topics using Goggle. Type pond boss forum and your topic
http://forums.pondboss.com/ubbthreads.php?ubb=postlist&Board=22&page=1 
