an A1200 is the next best thing. In this day and age the cost of owning and maintaining an A4000 outweigh the benefits in my opinion.
There is only marginal differences between an A1200 with 060 @50Mhz vs an A4000 with 060 @ 50Mhz. The cost for the latter will be at least 1.5x more. Still, if you've got the money to burn, you'll definitely earn some bragging rights
you also start off the bat with a unit with plenty of space for upgrades thus saving you having to relocate to a tower.