With the couple of fish, you will be fine in regards to the O2 in your pond. The good thing about a couple of fish, is that if one goes belly up, it's easily replaced!

Here's some pictures of when I renovated my pond.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=151543

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).