Thanks for the replies and I'll look forward to a reply from Jim.
Bad;
Welcome to the site first of all!
To answer your question(s):
The main difference between the two amps as you have seen is the power output.
The DCS amp is a plug and play unit with no other wiring or adjustment requirements.
The PSC needs a power cable ran to the battery. Also the PSC series amplifier has a
built in adjustable electronic x-over to filter out low frequencies that tend to distort 5.25" speakers.
There is also a sub output that can be used to drive an additional 75 watt amp.
The PSC also has an adjustable gain to match the output of your radio to the amps input.
As for your tweeters I cannot for certain comment on how they would handle the extra power, but from what I have
seen and done they should be ok.
In all honest with the CX speakers and PSC or DCS amp you most likely won't need additional tweeters.
With the additional features and power I would use the PSC amp if you like to tinker with things or want the ability to add later.
The DCS amp is really meant to be a plug and go basic system .
I have installed many of both systems and customers are alway happy with the improvements.
Hope this helps, Let me know if you have any other questions and or would like to order an amp. I offer site members a discount as well.
Jim