Thiel speakers--can you power them with reciever?

Or do they really need a separate amp?

I am getting the bug to make a speaker change(for my front L/R speakers), and from what I read, it seems like a used set of Thiels may be up my alley in terms of sound characteristics.

But, looking at their rated specs, they are rated at 4 ohms, with a minimum of 3 ohms, and have fairly low sensitivity at 87Db.

I'm also looking at used Vandersteen, Eggleston, Merlin. It seems like most of these have similar ratings to the Thiels.

Any thoughts? I am currently running my 5.1 system off a 130wpc receiver, but I do have a 5 channel power amp I could use. The receiver is not known for having much output into 4 ohm loads.