I've used ATF in the engine to clean sticky lifters before and it works pretty well. I sub one qt of ATF for one qt oil (on a 5qt engine) and change it out after about 1500 miles. Just be aware that you can cause oil seals to start leaking doing this (it'll also clean away dirt build up around the seals which may start weeping/leaking). I did this two times when I bought my 87 about 1 1/2 yrs ago which had a wicked loud VLA tap (1st oil change with ATF, 2nd all oil, 3rd w/ ATF and all oil since)...she runs smooth and quiet now...though every now and then I do get an occasional tap when starting cold.

As for the quality of the ebay lifters...I don't imagine there are too many companies that make the VLA's for our vehicles...so most are probably re-branded from just a few actual manufacturers.