Hey John,
Your excitement is refreshing.
I'd always recommend that, if you plan to do this for the long haul (i.e. treat your affiliate business
as a business), then you should build equity in your own website.
That said, while you build your own blog on your own domain, you can use those extra services (Blogger, Squidoo, MySpace, et al) as satellite sites that drive traffic and attention to your main website.
It's not to say that you shouldn't monetize your satellite websites whenever possible, it's just important to realize that while some people have had their blogs/pages without complaint for many years, others have those theirs in the blink of an eye.
Is it practical to build a blog and a lense on the same topic? Yes and no. It depends on how thin you'll spread yourself and whether you can find enough to discuss for both the lense and the blog.
What you can do is build your blog as the main focus and use the lense as a supplemental resource driving people to your blog where you can convert them into customers or subscribers.
Hope that helps,
~ Teli