I'd say:
50mg/day of Clomid for about 3 weeks.
20mg/day of Nolvadex for 3+ weeks.
I'm sure I'll get flamed big time (so it's a great way to start a debate), but I think people start post cycle therapy (pct) way way way too early. I think this is also the reason so many people complain about have Total Test levels of 200ng/dl after they've done post cycle therapy (pct) too (and then wonder why). Personally, I don't think post cycle therapy (pct) is going to help that much if you still have equal to 100mg+ of gear in your body.
So, given a dosage of 500mg/wk of Test Enth, let's say the half-life is 7 days (to make it simple). This means that at your last shot you'll have 1000mg of Test in your system. So I'd use the following timeline:
Week 0 - 1000mg (Last shot)
Week 1 - 500mg
Week 2 - 250mg
Week 3 - 125mg
Week 4 - 63mg
So even 3 weeks after your last shot you're *still* going to have supraphysiological levels of testosterone in your body. It would make sense then to start post cycle therapy (pct) between 21 and 28 days after your last shot.
The only valid counter argument I can think of is that it may take some time for anti-e's levels to build up in the body. I believe this is the case with Clomid to a certain extent, but I think Nolvadex is faster acting. Even then I think it would be safer to wait and start post cycle therapy (pct) 21 days after last shot.