Yes, it makes sense. I did this upgrade and works well. With upgrade you get dvb-s2 tuner which is default for d6750. The disambling and replaceng mainboard took about 20 minutes without special preparation, just need some accuracy. For internal wifi you can buy original wifi module, this not included.
For mainboard replacement ask on your local service, or eBay..., or
http://www.euroservice2000.abc24.pl/default.asp (this is where I bought from.). If you have anyone who can buy it for you in Poland, you can save (280zl for local buyers vs 80euro + shipping + bank transfer costs for international buyers. This is my experience. Do as you wish

)