Petes right about Amadeal but mass is good on a mill. Do you have links for the machines?
Edit: just done a Google and the Sealey seems to be a round column Mill Drill. Whilst nice and solid they can present some problems for users as you loose registration of the head (tooling) if you have to move it up or down for any reason. There are some ingenious ways round this but its basically a flawed design compared to what the Taiwanese and Germans have done with similar machines.
The Amadeal machine has a self ejecting drawbar so tool changing should be easier than on the Sealey but it shouldn't be a deal breaker.
The X3 mills are highly regarded (several retailers) but also look at the Warco WM series of mills, the 14,16 or 18 May suit.