A single amp install will make it a lot easier. You have a lot of choices as far as amps go, look for something 4 channels and 75 watts per channel if you want enough power for your components and sub. 300 watts is enough for most subs. With the V3 it is more than enough power as the SWS is a very efficient subwoofer. For a 3 way setup, the Audison SRX-3 is very hard to beat because it's a 3 channel amplifier with a class D sub channel which makes it very efficient. The MTX TA3404 can be had for under $200 shipped and I've installed it in an NSX before with very good results. The new MTX Thunder amps are one of the best choices for integrating with the OEM head unit although I know you are not using that. They have very cool switched inputs for high and low.
You really need to go to a good shop to choose what components you want and how much you want to spend. Find out what components you are going to buy first before you choose your amp. Then buy an amp that can meet the max RMS recommendations for the components. Everybody has their own preference for what components they will purchase for a given price range. The most popular brands are Boston Acoustics, MB Quart, Focal, Dynaudio, and JL Audio. I would not buy any set of components that I didn't personally audition. Polk Audio makes a set of SR6500 speakers that have been getting rave reviews if you can spend $600-$700 for a set of comps. But buy whichever components sound best to you. Bring a CD in and listen to a reference track to help you decide.