just to be clear, the digital receiver will not control the analog receiver/dish mover. You will have to select the satellite on the old analog box, let it move the dish, then select the same satellite on the digital receiver and select the channel there. Not ideal, and a diseqc dish mover would do that automatically. Unfortunately, with the Titanium ASC-1 being discontinued, and few sellers still selling some variation of the V-Box, using the old receiver might be the only option at this point (and without a doubt, the cheapest one).
As for a receiver, even if you don't want to spend much, try to stay away from the cheap stuff that is all over eBay. The Amiko that KE4EST sells are great receivers, and not a lot more expensive, and he provides great support.