Hey Wendy - Madagascar was absolutely awesome, I'd still rate this as one of the best trips I've ever done. Monique wrote up our trip and it was published in Rock and Ice as well as a similar one in Crux. You can see some of my pics from Tsaranoro here: http://www.onsight.com.au/gallery/list.php?exhibition=42
I'd guess Tsaranoro is the area you'd be most interested in? The Hosy Hara off the north coast took several more days to get to and were a bit expensive, not huge amounts of climbing but the place was by far the most idyllic I've ever seen.
Not sure about Tsaranoro in July, it might be OK. It's kinda in their highlands. I think we were there late August into early Sept and conditions were good and certainly warming up so it might be OK earlier. I think it might have actually been getting hot when we left and that'd suck on those long multi-pitch routes... I can give you email addresses for some French climbers who would have been there at that time if you get serious about this.