suggestions on best amp for my system

[cembros]

ok so i have my lsi15's, lsic, lsifx, and psw1000. They are all connected to my sony3300es which has 7.1 pre outs. Im looking to connect a seperate amp and im looking for suggestions as to the best amp that i can get for the setup i have without spending extra money one features that my setup cannot accomadate. Also i dont know weather i want a 5 channel or 7 channel amp. I know my receiver can matrix 5.1 singals to 7.1 through hdmi, ut i am unsure if it can through the analouge connections. This is a concern for me because i have heard that with high end compenents (specifically blu-ray players) this is the more desired option. Please correct me if i am wrong, and any imput is greatly appreciated.