I think the questions that you to answer first -- for yourself, and maybe for those who may respond to your post -- are: how serious are you about home theater, and based on this answer, what cost is justifiable?
If your primary interest is audio, rather than HT, and you want a decent but not outstanding HT system, then I'd say the AVR307 will probably do a perfectly competent job handling your HT needs.
On the other hand, if you really want top quality HT sound, or you know in your guts that you will start upgrading almost as soon as your HT is installed, then you will probably be happier getting the B&K separates now.
If your primary interest is audio, rather than HT, and you want a decent but not outstanding HT system, then I'd say the AVR307 will probably do a perfectly competent job handling your HT needs.
On the other hand, if you really want top quality HT sound, or you know in your guts that you will start upgrading almost as soon as your HT is installed, then you will probably be happier getting the B&K separates now.