Ergopharm's 6-OXO and Gaspari's Novedex XT(which I assume you are talking about, as Nolvadex is hard to get and is on a much higher plane than Novedex) are both good products for providing an anti-estrogen effect.
For an anti-estrogen effect of the type that you seem to be looking for (i.e. chest tightening, ridding of excess water) I would go with the Novedex XT from Gaspari for a period of about 6-8 weeks and cycling off from a maximum of 4 tabs per day down to one or two in the last week. I have had friends use the product and they have said that Novedex really provided a good 'leaning out' effect, as well as providing moderate strength gains. One for instance, also had blood drawn afterwards at a physical right after use of the product, and it showed that his liver enzymes had not been spiked in any way and were at safe levels. Although, this should be expected as neither of the two can be described as pro-hormones either, and should not have any negative sides to your liver.
Now for the popular pre-workout drinks that are out......that's another story