in that case mate you should be able to get a decent secondhand Snap on CTU4850HO off of ebay OR ring your local dealer and see if he has one that he has taken in P/EX against a new one!!

Do try and and get the HO (High Output) model as its slightly more powerful than the standard CTU4850 and its exactly the same power as the newest CTU6850.

A decent secondhand Snap on Cordless 18v gun will be better and more powerful than any of the other new ones you have mentioned and also if you ever damage it badly Snap on will refurb it for £100 regardless of what it needs and it will come back to you looking like new!!