I'm looking for small aeration units to put in my grow out ponds. I'm sure with enough looking I can find some, but was hoping there may be some good advice on here. Any advice is appreciated.

Oh oh, I can help!
Using this in the garden pond. Efficient, quiet, and comes with a nice diffuser:

Aquascape Pro Air 20 Pond Aerator and Aeration Kit

Please check to see if Pond Boss supporters have one before going to the usual suspects.

Larger than it looks in the image.

RC51 talks about the ECO pumps in this DIY thread...

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=245867&page=1

AND DCQuarterCircle seems to like his AP Pumps...

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=511966#Post511966

I can't vouch for the pumps, but that is where I would start researching.