i went to configmyrig.com and selected the options to hit something close to 5mh. here is a screenshot:
http://s28.postimg.org/uayj19exp/Screen_Shot_2014_01_09_at_11_21_58_PM.png
i'll be scrypt mining at a multipool and the total that came up for the complete setup is about $5,000 seems like alot but let me know if you have any suggestions. What i'm wondering is how many PSU's would I will need and what kind is recommended? I'm thinking it would be a gold or platinum for the PSUs but i'm not sure how many and what kind would suit 6 Radeon R9 290x's. Also is the motherboard & cpu selected good enough? I'll be using a milk carton for the rig instead of a case so i'll need to get a hold of a good one.