It is a common belief here on Audioholics that Bose are overpriced for what you get. You can see by my signature that my rear surrounds are still Bose cubes, although I agree with most people here in the fact that there are better options. Especially for the money that Bose charges for their equipment.
Bose does a great job of marketing their products for convenience, supposed sound quality, and asthetics. Once I went around and listened to the other options out there I too found out that there are better options for the price. Unfortunately, I still have to replace my rear speakers (and subwoofer) to complete my setup.
By going with the HK avr247 instead of the avr147 will only give you 10 more watts/ch and 2 more channels (5.1 to 7.1). This is a nominal amount and should not be much, if any, of a noticeable difference. The biggest difference you can make would be to get different speakers instead of the receiver. Lucky for you, Bose is quite popular with people that have not heard better quality, and you can most likely sell them on Ebay for a decent amount of money to put towards your new setup.