SDSoC

You make some valid points about why it may not make sense to switch horses, and management usually underestimates the time and cost of making changes like this, but you should at least check out what Xilinx has to offer. Download a free version of the tools, play with some reference designs, etc. Maybe even get your boss to pay for some classroom training. I was pretty impressed with Vivado. Xilinx has come a long way in the last 4-5 years. As for an Altera equivalent for SDSoC, I don't think so but I have not been paying close attention.