i was wondering what peoples opinion on coilovers vs. bags, what is a good company for bags and a good company for coilovers.

If you had any idea as to what you started by asking the opinions! The answer to your second question, without a doubt will be, American Air Suspension.

http://www.americanairsuspension.com/

Here is a link to a thread, to get everyone's opinions.

http://www.lincolnvscadillac.com/showthread.php?t=36168&highlight=air+ride

This topic has been discussed by great length at both this forum and other mark forums. I see you are looking for a swap to mustangs hubs in another thread, that is also heavily discussed. People have been doing these modifications for many years with no problems at all. There are ads at the right side of this forum that link you to companies that can help you.

I wouldn't even attempt to take a wrench to any car without mastering the magic of the Search feature first. http://www.lincolnvscadillac.com/search.php?f=6