Changing the rails on the X and Y axes to supported and using a Chinese water cooled spindle would make a huge difference. The Kress 1050 is a very good router, but it's still a router not a proper machine spindle so for instance suffers from a lack of rigidity and higher run-out. If you're getting that machine I'd advise making changing the rails to supported a priority, then get a 2.2kW spindle when you can afford it. The 2.2kW spindle is better since it uses larger (ER20) collets and will get marginally better power at low speed.
I still don't think that machine is a good price considering the total cost of the components bought from China, but it's hard to suggest anything better without saying make it yourself.