iMac or Tower?

Any designers out there using the new 2.0Ghz Intel core 2 duo iMac? I’m torn between upgrading from my G5 dual 2Ghz to either the 2.0GHz Intel iMac or saving for 1-2 months and buying the new entry level quad processor tower instead. I’m a web designer/developer but do I really need two processors and a super powered graphics card? My dual 2Ghz G5 is so slow when running CS3 apps, I figure it’s because CS3 was intended for Intel Macs. The worst is when switching from AI to Flash, there’s about a minute of lag time and it drives me crazy. The iMac seems suitable considering I don’t do any video editing or play games on my Mac. Is it a good machine for the job?

Second question, would more RAM resolve my lag time between switching apps? As well, it takes forever to boot up. I’ve got 2GB of RAM now, would it be noticeably better if I just dumped in 8GB of RAM?

Thanks for any advice!