How do I get a good selection of regens with only English leagues loaded?

I only want the English leagues for a fast processing time but I also want some good regens coming through. Which database and players from which nations should I load? My limit is about 75,000 players I think.

Quality of regens is NOT dependent on the number of players loaded.

I'm not sure but I think the regens are just luck of the draw.

Are you on about the "amount" or "quality" of the regens?

So it's OK if I just have say 9000 loaded? I am on about the quality of regens.

From my experience if you only have England loaded you will still see a few good regens. I play with a friend on a network save we have the same but after about 5 years they start drying up. Probably because the game is waiting for the likes of Tevez to retire befor releasing more Regens. Id say if your only going to be managing in england just load it up and have the major nations as view only. That way the player database should be bigger so you will get far more regens coming through. The quality however as the OP sated is i belive random.

I think the quality is not entirely random but is tweaked so that the average potential ability of all players in the game remains close to consistent over time. I don't know this for sure, but I'm guessing it's likely.