There's a lot of good options as far as what to buy but I wouldn't worry about the nylon string business. The way to build calouses is to play,play,play. Now your finger tips are gonna hurt for a bit, that's when a lot of beginners give up but you just have to keep on playin'. I have a 20 year old Ovation legend that has incredible neck action if you can get used to the rolly polly round back. ( they make a much thinner bowl design these days. )

If money is no object get Jim Olson to build you one. http://www.olsonguitars.com/