My domain mydomain.com is registered with GoDaddy. I wish to host my Tumblr blog on this domain with Nearly Free Speech hosting.

My active nameservers at GoDaddy already point to my authoritative ones at Nearly Free Speech which is working. However I'm baffled as to how to get my correct configuration to point to my Tumblr.

Preferably I'd like

(A) my domain http://mydomain.com to host the blog and have http://www.mydomain.com redirect also to http://mydomain.com.

If this is too difficult my next preference is

(B) to have http://www.mydomain.com host the blog whilst http://mydomain.com redirects to http://www.mydomain.com

My third preference is to have

(C) a sub-domain like http://tumblr.mydomain.com or http://tumblr.mydomain.com to host the blog and I guess have http://mydomain.com and http://www.mydomain.com both redirect to it.

I've tried having two aliases mydomain.com and www.mydomain.com pointing to my permanent Nearly Free Speech IP at mydomain.nfshost.com and when I try to add:

(1) an A record pointing mydomain.com to the IP 66.6.44.4 as per Tumblr's instructions it tells me I already have the bare domain as an alias so I cant do that.

(2) the A record on the www.mydomain.com alias. I can do this with either www.mydomain.com set as an alias or not. But when I tried this with mydomain.com set as the canonical name the result when visiting either mydomain.com or www.mydomain.com was both of them continually redirecting to each other until an error was thrown.

So I was wondering if there is a ninja that could save me some hair-pulling and tell me the correct way to config A, or else B, or else C.