Well first things first - assuming you have made the business case for buying in the USA - then you have the transport (which of course you have factored into your business case!! )
You can either
a) get it crated and shipped
b) have it delivered
v) join in with the ferry trip and make it an adventure - taking an professional with you
you note I haven't said ferry it yourself. This is a possibility but
1) you must be IR qualified
2) the insurance is likely to insist on previous experience - though how anyone does their first Atlantic trip I don't know

The decision to get it crated and shipped or have it delivered is entirely a matter of personal choice and economics. It will cost you the same to have it delivered as if you went on the trip with the exception of your own costs (flight there, hotels food etc). I suppose that boils down to your risk taking quotient, I went across in September and we had 50 knot winds, ice at 5000 - Believe me if you come down you are unlikely to be found. If you do ditch successfully the life raft will be 50 miles away seconds after you've opened it. But there's an adventurer in all of us and you can combine the trip adventure  with a load of learning.  The environment is good in the USA for intensive learning and the price is attractive.
So far I am coming down on the side of going along for the trip as opposed to having it delivered. But lets face it there are additional personal costs and it would be nice for it just to arrive - ferry costs for which I have seen quotes  ranged from $5500 to $15,000 all inclusive. Most professional outfits are about middle of this range I guess.

I didn't research crating because I had more or less made up my mind   to do the adventure. I hear from one correspondent that this is about $12,000 - not much more than ferry trip and probably cheaper if you include hotels insurance and flights. This is getting Cirrus to do the thing to Bembridge as I understand. Sounds a bargain with the dollar rates as they are. There are urban myths around about planes being shipped over as deck cargo and their G meters being off the scale when they arrived. I think a Cirrus supervised shipment would allay those fears. Its certainly an option for busy people.

As for choosing a ferry company I'd say ask around not once but 10 times. ask especially those who have handled imports such as the Danish company EFT, the people setting up Trust's for you and especially your broker in the US. I cannot comment further as I have experience of only one but it worked for me and I was happy with the price and outcome - they sorted the paperwork and the arrangements along the way.