MKII Upgrade from standard - Noob

[HARVS1789UK]

Yes, I realise things like this have already been covered and yes I have looked through all the stickys. I am however a total noob in this respect and even most of the dumbed down articles use terms im not familiar with.

Basically I want to uprate everything audio related in the car. Its a 91 MK2 and other than the head unit everything is standard.

My question is this....If i went for some aftermarket speakers (5.25" for front doors, 6 x 9" for rear and tweeters?) as well as a modest sub (10"/12"?) to be house in an arch build in the boot and run it through an amp placed behind one of the rear door cards.

Would that:
A) leave me with a good system with good sound quality (assuming I don't go cheapo on parts) and
B) what difficulties could I encounter? Would most 5.25" speakers fit behind the original speaker grills etc.

Ive seen people suggest its a better idea to run all the speakers through the amp not just the sub, is this beneficial and does it require an amp with more channels etc?

What is the difference between 2 way and 3 way speakers? coxial/component etc? its literally like latin to me so any help would be really appreciated including any good places to buy from as all I seem to find is horrible bright logo covered speakers in huge sub housings etc that look ready to go straight into some chav mobile? Im more looking for top sound quality which is hidden away. All go and now show I guess!

[dragonfly]

Due to the angle of the stock door speakers - some prefer to have angled pods which also allow them to house 6.5" speakers.

Most 5.25" speaker will fit behind the stock grills.

Ditch the 6x9's - decent components at the front and a sub in the boot all amped will give you a good sound.  The 6x9's will just muddle the sound.

Components are basically where the mids/bass speaker is separate to the tweeters with a crossover to split the signal.

2-ways/co-axials are speakers with the mids/bass and tweeter all together.

[HARVS1789UK]

Ok, most of that makes sense.

Im not keen on the angled pods as I want to stay as original as possible.

Am I right in thinking that component/3 way speakers would provide better sound quality, but id have to connect them up to the tweeters (and upgrade the tweeters?)

As far as ditching the 6 x 9" simply disconnect them then? Hopefully there is a connector which I could disconnect rather than cutting the wire/stripping it out, so that they could be reconnected if anyone wanted to?

What would be a fair budget for the above (amp, sub, 5.25" component speakers, tweeters and wiring) also am I likely to need to upgrade my headunit to run all of this well? (Currently some standard off the shelf cd player probally from halfords or similar, might be pioneer)

Thanks for the pointers dragonfly   

[dragonfly]

With components you get the mid/bass speaker, crossover and tweeter.  By separating the signal you get a better sound. Rather than a speaker trying to cope with the entire musical range it's split so the tweeters handle the top frequency and the mid/bass covers the middle and the lower frequencies.

With 2-ways you already have a tweeter as part of the speaker so adding another tweeter might make the sound too harsh.

Yes if you already have 6x9's you can simply disconnect them. It is a big speaker and if you add a sub and only have 5.25" speakers at the front you can see how the rear sound (staging) can be muddled.

Budget really depends on you and how much you want to spend. £200 can get you a nice headunit and £150 for decent 5.25" components. 10" sub in a box would be about £100 with an amp at £200 to power the lot. Wiring kit will cost you £25. You can spend more or less on each component.

Ideally get down to a decent ICE shop and hear some stuff (take your favourite tracks). Then buy what sounds good to you.