Thanks everyone for your replies, i'll be looking into all your suggestions over the next hour.
Hey Robin as far as the criteria for 'Composer' as opposed to 'Songwriters', i suppose i'd include the distinction of a Composer usually writes the parts for other instruments in the ensemble (or in a lot of cases, an orchestra, where there'll be many instruments they have to write music for despite not being able to play them, ie: the harp), and generally focuses more on the instrumentation/melody/accompaniment etc rather than just lyrics & chords (which is what would constitute a songwriters main role).
Some Composers even venture into Orchestration & Arranging which is an art in itself (it can be equated to a Director editing his/her own film, instead of letting someone else do it), and that deals with deciding what notes of a chord each instrument can play in order to create harmony & texture, they also have a deep knowledge of the 'timbre' of all the instruments & know which types of brass & woodwind etc (and what quantities) sound best together etc.
So yea that's a basic idea of the distinction between Composers & Songwriters, the lines can be blurred now & again though.
Ian I totally know what you mean, the way the strings all blend in certain pieces and the textures & moods created in Orchestral music is amazing. For example, some of Mozart's most famous symphonies could be played on a single Classical guitar whilst retaining all of the main voices, but when it's played by an orchestra, it just becomes a completely different animal.
Also i like what Hans Zimmer says about an Orchestra and how it can never be fully imitated or replicated by technology, he says there's nothing like a group of mabye 60 musicians all playing together & having a Conductor steering & aiming their collective intent in one direction, hence the importance of a good Conductor.
Been coming across quite a few (commercially) unknown composers recently who are quite skilled, check out this film composer i discovered on Facebook, really like this piece in particular
https://soundcloud.com/anita-andreis/hiraeth
Me playing Joe's actual Ibanez Tubescreamer pedal -
http://www.youtube.com/watch?v=76jk58_vl2s