1) Buy the Ascends, Onkyo receiver and HSU/SVS sub
2) Take $5 and buy some blank stickers
3) Write Onkyo 6 times
4) Place a sticker over Ascend and HSU/SVS logos
5) ???
6) Profit!!
Better yet, take some of the leftover budget and buy a universal remote. Program it yourself. Something like a Logitech Harmoney that had the real simple UI. Then it won't make a difference what you get him.
All he has to do is push "watch TV" and the TV will turn on, receiver will turn on, cable box will turn on, and the receiver will switch to the proper input and sound settings. He wants to watch a BR movie? Push "Watch Movie" and the cable turns off, BR turns on, receiver switches to the right input, and he's off and watching a movie. Assuming you set everything up correctly (it's really easy honestly).
You have a golden opportunity with that budget to get him a system that will last him for many years and put a smile on his face every time he sits down in front of it. Don't waste that trying to make everything one brand.