Components into a mk4 golf

[Mr_Orange]

Hi,

Got a MK4 Golf, with Gamma 8 speaker set up.
I've upgraded the headunit to a Kenwood DPX503U.  Sounds great on the standard speakers, but as soon as I really crank it up or twiddle with the bass settings it all goes a bit waffly.  I've never been keen on fading back to rear speakers, so its set 99% to front.

I'm interested in fitting some components up front, so got a couple of questions.... 
Can component tweeters be shoe-horned into the existing speaker locations (at wing mirror)? 
I know I'll need some adaptors for the door speakers, what's the best size speaker to go for, 16.5cm or 17cm?
Also what's the craic with speaker impedance?  The head unit states 4-8 ohm, is less more or more less when selecting speakers?

[Mr_Orange]

Little bump.  Need some guidance here please 

[pickles]

http://uk-mkivs.net/forums/t/287271.aspx

[Mr_Orange]

Thanks mate, seen that, was after some further info.

Whats the deal with impedence?  I see most speakers are 4ohm.  Head unit it rated 4 to 8 ohm, is less preferable?

[T_J_G]

4 Ohm's should be fine. 4 Ohms will draw more on the amplifier resulting in a ''better'' sound.

[stuartb3502]

You just need to match speaker and head unit/amp. Impedances.  Lower impedance will draw more power from the amp. if the amp. can manage it.  Lower impedance needs better ampoification to maintain control.  Probably easiest to stick with 4 ohms unless you know what youre up to. 

S.

[Golf_GT_TDI]

How about Rainbow IQ line or Eton's those are both direct fit