Many hybrids are hardy, docile and friendly (though some are more flighty than others).
Ex batts are all very deserving of a good home but will be a challenge if you haven't kept hens before as they are prone to health issues.
I would be wary of keeping hens of different sizes together as you may find the smaller ones get picked on. Much also depends on how much space you have e.g. will they be able to free range or will they be kept in a run - some breeds of hen are happier to be confined than others. Similarly some are better flyers than others which may be an issue with your neighbours!
Many of the hybrids have been bred with egg laying performance in mind. They can produce a very large number of eggs in their first year to 18 months but that can then tail off quite rapidly. They also tend not to be so long lived.
I started off with, and still have, 2 rhode rock cross hybrid hens. I love them to bits but as they start to approach their 2nd year they are both developing egg laying problems. When I get more I think I will opt for one of the pure breds which may not have that initial egg output but that will lay for a longer period.
If you go to the omlet website they have quite a useful section on the various breeds which you may find helpful:
http://www.omlet.co.uk/breeds/breeds.php?breed_type=ChickensI am sure you will get lots of messages from others with their opinions and preferences.
Hope this helps and good luck