The thing is that if you just have a website with basic information, it is as good as not having one. You need to put some effort into it by sharing your knowledge online. This is tough for a lot of people as writing and teaching is a skill that not everyone has. But it does help if you do it with a specific focus.
It's a bit like perceived scarcity. Building a flashy portfolio website really only says two things: "I have free time on my hands", and "My demand is so low I have to put effort into advertising". Sure, if you're just getting started, that might be the brand you wanna build. But as you gain momentum, having less of a public brand is often better for business than having more.
It's counter-intuitive, I know; and maybe my experience was colored by the freelancers I happened to know at the time. But it convinced me enough that I took down my website while I was freelancing full time, I only put it back up after I quit, (to use as a resume to get full time job.) Removing my online presence did wonders for my business, and that's why I recommend it.
As for portfolio, just go with linkedin and whatever you feel you would like to sign up for. These hubs are the first place people check. A personal site is nice for blog posts and such, but I wouldn't put more effort into it than a wordpress site with contact info and links to things you already made. Stuff you write, if you do at all. See weatherfactory biz for an example
However, meeting and talking to people, in other words just plain old sales work is vital, too. That's where a decent website helps a lot: You can refer people interested in your services to your website for further information, testimonials, previous projects etc.
In other words, potential customers probably won't find you via a Google search (unless you're a high-profile specialist or open source contributor in your area of expertise) but a decent business website will complement the rest of your sales efforts.
I just wanted it to be kind of a better "business card".