Well I did the upgrade over the weekend. I went to my local car audio and listened to some speakers and settled on the Alpine SPR-60C splits - mainly as they were on sale and couldn't pass up on the price but they did sound a lot better then the S and G type speakers.
I also had an opportunity to pick up the SPS-410 coax speakers and offered them up to the 3.5" dash plastic mount (in store ) and there is no way they are going to fit without a lot of work and just not worth it IMO.
The woofers fit very snuggly into the existing door plastic mounts (cutting the old speaker out) however there was a tiny air gap between the existing speaker mount and the alpine and screw cut out slots which needed to be sealed. The neo magnets on these woofers are suprisingly small and don't protrude very much at all.
The tweeters were pretty straight forward to fit - just used the flush mounting kit onto existing dash plastic mounts under the dash grills. I tried to use the stealth mounting kit but couldn't remove the tweeter grill (glued on) and didn't want to do damage the tweeter. Anyway, under the dash grill you can't tell anyway.
The cross overs came with prewired cables and were way long enough to plug into the tweeters and splice in to existing speaker wiring.
Sound wise - very impressed. I found that by fading 90% of the sound to the front and these speakers really do sing. From out side the car you can really hear the bass. Bass is very strong and tight. The tweeters are very crisp and smooth at the same time. I've had the head unit up very loud and haven't noticed any distortion. I might put in some sound dampening later.
Two tips, when removing the doors - take out the white plastic clips and slot back into the panel, ie don't leave in the door. The rubber window seal slides off the door panel and is fit to the door before puttting the panel back.
Now that I've whett my appetitie - I can't resit putting in an amp and sub - but maybe another day.... I'll try and post some pics later.