A couple of minor comments:
1) There is no evidence at all that drinking green tea as a beverage (or taking green tea extracts in tablet or capsule form) has any systemic effect of 5a-reductase inhibition, with subsequent DHT reduction. Please note that Liang's and Hiipakka's study was almost entirely in vitro; the part about how the rats' internal organs were affected was when EGCG was INJECTED into them in large doses, not given to them in their food or water. The reason for the failure of green tea to inhibit 5a-reductase systemically when taken as a beverage is probably because EGCG is very poorly absorbed from the GI tract. And as I've said many times before, there's still a distinct possibility that TOPICAL applications of green tea (or an extract) could be usefull for controlling hairloss, even if taking it orally as a beverage is not. There are both animal and human tests showing its ability to inhibit 5a-reductase, when applied topically.
2) There is evidence that caffeine may be an important co-factor for at least SOME of the general health benefits that you get from consuming the polyphenols in green tea, so I would use the caffeine-free versions with some degree of caution.
Bryan