maybe start out at 40mg's ED? and bump it up if you don't feel its enough after a while. you could probably see results on as low as 20mg though with the spa i heard. might be best to start low and see what happens week by week, and bump it when needed.
Just keep calories in control, since anavar is pretty mild.....you should be alright with the weight gain if you keep calories at or below your maintainence. you should def try a low dose if you dont' want to gain any weight though. go with like 20mg or so.
yeah, let us know how it goes. i am going to be using 50mg of chinese (non-IP) anavar with a lower cal diet myself, and hope to keep my weight where it is.....but lose some fat and cut up. i wouldn't mind some fat loss and muscle gain though, that would be great to gain weight in that respect.