Hello there all, bit long but i need help please,

I am going to buy a home cinema type of setup for my room (approx 6 by 5 meters) and i really need some expert help please as i am a total novice.

I have:
1. An hdmi 32 inch Panasonic TX-32LZD80
2. A ps3
3. A music library of mp3's on an external hard disk

I would like to combine the lot into some kind of surround sound (5.1/7.1) with speakers fixed in the four corners above the picture rail (approx 3.5 meters high). I want something with a real quality sound.

I want to be able to listen to my music library through the speakers, at the moment i use my laptop.

From "internet" research it seems i need an AV receiver and a set of speakers to attach. Or separates i could upgrade. (along with lots of confusing stuff about wires). But i do't really get how to organise my mp3's through it. (can't use the ps3 for it its far too convoluted).

I've been looking at the Onkyo TX-SR308 av receiver as the reviews seem excellent and it it a bit cheaper now the newer model 309 is out.
I can buy it for £150 (without speakers),

Please, is it a good one, and what speakers would you recommend?

I have also looked at these 2 all in one sets.
Onkyo HTS3405
Onkyo HTS5405

My budget is not vast but for the whole package i could pay upto £300 or a bit more. (unless you are persuasive.)

All help is greatly appreciated. apologies for the mishmash long post.