Hi Mel - I imported my french '73 CSL from London to Oregon via Seattle last year to use in the NW Classic rally. I've used these guys twice now and 100% positive on the experience - they operate throughout Europe.
http://www.carseurope.net/contact-us
Bringing your Euro car to the US is pretty easy and Carseurope took care of everything. For a nice CSL, its worth paying for top service. I used a 20' solo container, but would have split a 40' if the shipper was able to find another car going to the same destination. In no way would I recommend roll-on-roll-off to save money.
No crazy legal, customs or emissions requirements (even for CA if 1973 or older) but there are a lot of little items that add up the cost - port and agent charges, customs x-ray, local delivery, insurance, arranger fees, etc, etc. And don't forget US import duty is calculated on the value of the car plus shipping.
You will have to get it state registered once it arrives - the car is unregistered but in your possession once it clears customs so I suggest getting a temporary (usually 30-day) road permit so you can drive while you go through the license process; its not difficult, just follow the rules on the DMV website.
PM me directly if you want more info.