If you have just a few websites and they are low traffic, why not just pay for vhosting some place?

I was hosting a couple low traffic web sites from my home  office and decided it was not worth it. I went back to vhosting. 

If you are set on hosting out of your home or office you might consider a low end box for your web server.

I use an old HP single core AMD laptop with 3GB RAM as a LAMP dev box that has enough go that I think it would make a nice public facing LAMP web server.  I've always thought a netbook might be enough power to run a LAMP server for a handful of low traffic websites.

I know some are cringing at what I said.  I'm not talking production here.  This is simply home office stuff.

And if your other server is strictly for file storage then you do not need much of a box there as well.  I would think storage would be more important.  I'm thinking and i3 with 2gb of ram with lots of storage.  And the i3 might be over kill since it is for storage and will be running Linux.

I ran CentOS 5 something on an old 1g Celeron w/256mb ram a couple years ago. Just command line.   I installed QmailToaster on it and it ran well as a test. 

Based on my experience for what you are talking about you really do not need much resources, especially since you are going to be running Linux.

Keith