Thanks to everyone for those informative replies.
This is great news as I was already thinking of going with an Alabanza "reseller" and then server. I really like their control panel and have had practically no downtime with my own 3 sites which I have with them through "resellers".
As for my second question, perhaps I can express it a bit better:
If my hosting company was, say, simonshosting.com, is it better to use nameservers of the form ns1.simonshosting.com or to use a different name like ns1.simonsdns.com for the nameservers?
Or maybe it makes no difference one way or the other?
Thanks again - I am already finding this forum an invaluable resource and I haven't even started hosting yet
I look forward to the day when I become knowledgable enough to help others out in return!