Bitcoin Rig and Program Questions

as you may or may not have noticed, i did not know exactly which forum to post this in so i posted it in a few. Could a mod please direct this to the appropriate section? 

To begin, ive done a little research on the topic, and have purchased some of the components i need. 

Ive also tested a program or two for bitcoin mining on a rig i had put together for my sister. 

Sisters rig:  

Intel Core i3 2120

Some gigabyte Z77 motherboard.

MSI 560ti power eddition or something.

550w 80PLUS PSU

and 8gb (2x4gb) of 1600mhz ram CAS 9 from gSkil


The Mh/s from that rig was very underwhelming. about 180Mh/s on the GPU and 30Mh/s on the cpu and i aquired only about 0.02 bitcoin in a pool after about a week. i also learned that AMD Cards are generally much better at bitcoin mining.


I recently bought a WORKING AMD 6990 from kijijifor 300$ CAD, and and going to pair it with my QX6850 on a evga 780i ftw Board, at least until i have enough cash to upgrade my CPU, MoBo, And RAM. The PSU i have is an old OCZ GameXStream 1010w. i DONT Think it is 80PLUS, And i believe it has about 6 12v rails and needs to be upgraded as well. 


My question was What would be more beneficial? getting an i5 3570k and another AMD 6970, or a I7 3770k and NOT get another GPU? 


i know that in terms of gaming, the differance in performance from one processor to another is not that great, And i dont do any rendering. 

If i do go with the 3770k, it would mean that i will wait longer to get another GPU. the same person who sold me the 6990 has a Second 6990, and two 6970 cards that he would sell to me for 650$ CAD. All of the cards are working. Ive varafied this personally. 

I want to maxamize my Mining while still having a functioning gaming rig. 

The second part to my question is what Mining program works best? is there one that prefers CPUs? One that works better with multiple GPU Video cards? 

and what would yeild better results? Being a part of a REALLY Large pool and making fractions of a bitcoin at a time? Or going solo, and trying my luck at the jack pot?


Also, Could we have a Bitcoin thread? i often have many more questions but many of them escape me right now. Maybe in the hardware section? Possibly the coding section? i dont really know where it would fit best.