Mobo: I would go with a Gigabyte GA-MA790GPT-UD3H its 144$ i think maybe you could find it during a rebate for 100$
Case: Cooler Master Elite 430 is a great case and only 80$ if I remember correctly
^ he is crazy to put AMD mobo for your intel i3...
go for any b75 or H77 mobo, any brand will do. choose the cheapest one on your country