Is it possible in the guanacaste area to get the same exposure to wildlife as I would in Manuel Antonio?

sort of.
i had a family of howler monkeys living behind my house in Playa Hermosa:

http://costa.rica.typepad.com/playa_...ome/index.html

But,at Rincon de la Vieja youre almost guaranteed to see lots of wildlife.
Go with Mike at Papagayo Vargas Tours based in Hermosa.

Thanks, I know I've posted before about trying to figure out where to go. I think Manuel Antonio sounds amazing, but we are traveling from the end of July to beg. of August and so figured somewhere along the north pacific coast would be drier, but I don't want to miss out on the wildlife.

Nosara would be a good choice to see lots of birds and monkeys around your place. Recommend Giardino Tropicale.

I haven't heard of Nosara. I guess I'll have to look at where that is located.

Manual Antonio is yucky. Stay away.

Tamarindo is now the definite tourist spot, so pick another Guanacaste Beach if you are people adverse. I still like Tamarindo though. Would stay at Hotel Diria or Capitan Suizo or Cala Luna. Diria's dead center on beach and town action. But no wildlife really left in Tamarindo. Go south.

I wouldn't call Manuel Antonio yucky.

It is one of the more popular places in CR - for a reason. It is easily accessible, has a wide choice of lodging from budget to luxe, has outstanding views and a wide variation of wildlife. It doesn't compare to the Osa of course, but between MA and the Guanacaste area, I would pick MA myself.