Having recently replaced my speakers and installing an amp I spent I fair amount of time researching options and searching for best value. For speakers I went with Pioneer TS-D1602R 6.5" 2way Coaxials into front and rear doors, paid $145 a pair from Super Cheap Audio (an eBay store, not the large chain with the red shops) and Infinity Reference 9603IX 3way 6x9s on the rear shelf which I got from RYDA for a mere $128. For the amp I went with the Pioneer GM-D8604 digital 1200 watt 4 channel capable of 100wrms per channel, $221 from Super Cheap Audio. Hooked the amp to the front door coax's and the 6x9s, left the rear door coax's and factory tweets running off the head unit. Add in wiring kit, sound deadener, split loom and electrical tapes this project ran to about $750..........Sounds freakin' amazing, well worth it. Sounded great with just the doors done but went to another level once the 6x9s and amp were powered up. The Infinity's are powerful and smooth, the whole setup makes plenty of bass and sounds clean.
If you are just doing the doors I found the D series Pioneers 2way coax's to be a good blend of quality and value. You don't have to change the factory dash tweeters, you will notice a big improvement just replacing the door coax's.
Note that I have no experience on VE's. I have heard that VE factory premium systems have 2ohm speakers, the Pioneers above are 4ohm. Look into this before you buy anything as if you are not going with an external amplifier you might be limited to 2ohm speakers. Increasing speaker resistance lowers the amps power delivery, for instance if your factory head unit delivers 20wrms into 2ohm it's power rating will halve into 4ohm. This is an important consideration, no point installing better speakers that reduce your systems available power.
