So you want to change the entire lineup or just the front 3, I noticed with the effect speakers, surrounds and rears, as long as they are decent they will do the job, what you have is decent...
So just changing the front 3 will help the budget too...
Ascend 340se's - for 2 will be around $900 shipped...
Or a 340 center with 170's if the 340 are too big for you- $675
If you want to change the entire set add 200se for all your surrounds
You can get 2 focal 806v's with a 800v center for $1150..
Wharfedale diamond 10.2' with center and surrounds close to your budget..