Absolutely my good man...i live for this shit.
Nektar is NOT canterbury though, they are from germany and helped for the "Krautrock genre". Canterbury is referring only to the english (canterbury area) bands, such as the ones ive listed previously in this thread.
For more bands like Nektar...check out the following bands for starters:
Novalis (sung in german, but similar musically to nektar).
Triumvirat (this band became very popular in the USA and abroad as well...due to their english vocals despite being german and undeniably catchy melodies in the majority of their songs...ESSENTIAL! Grobschnitt is also a great band, very symphonic and melodic, with cool concepts on some albums.
id also check out "Focus"...theyre from denmark, but absolutely amazing all the same...and somewhat similar to the Nektar or "krautrock" sound.
If you like those, then i have some more extreme and experimental german krautrock bands for you to check out. just let me know if youre interested.
As for bands a lot like camel's mellower stuff....i have dozens of bands you could try, but heres some starters:
Dancer - Tales Of The Riverbank
Matching Mole - Self Titled
Fantasy - Paint A Picture
Cressida - Self Titled
T2 - itll all work out in boomland
All these bands do have harder songs, like camel...but many are mellow and chock full of melody like the "mystic queen" or "air born" examples you requested.
Hope you enjoy these, let me know if you need some help finding MP3s, ill see what i can do for ya!