how much are you looking to spend? The TS6900 are good to go, but the budget will determine the amp and head unit. The guys here will point you in the right direction.
Well on the low end the Soundstream PN4.1000D would work, and on the high end you'd have the Arc Moto 600.4. Talkin $130-600 here, but there are options in the middle and thats where the more experienced folks need to come in and help.