I've always used Kona "snow" for all my embroidery. In years past I did use a 200 thread count fabric from Springs that was great but I think it's long gone. IMHO any color of Kona is good depending on what you are doing. I also like Bella (thunk its from Moda) - have charm squares that feel really nice and seem to be about the same or nearly as Kona but haven't tried it out yet.
I still do not understand the use of fusible interfacing on the back of your fabric before embroidering. I'm self-taught and absolutely never travel with my thread more than 1/4". It's a real pain when you have to do french knots (I actually use colonial knots - they come out much nicer) and they are spaced too far apart but I r learned how to manage. I read something long ago - like a really long time ago �� that said your embroidery should look as good on the backside as it does on he front. I'll never be quite there but mine mostly looks pretty good on the back. Probably should since I've been embroidering for 50 years. Went to a small college and girls couldn't leave campus without written permission from her parents. Found thread (5 cents a skein) and preprinted pillow cases at the 5 and dime and just started.
Sorry for for going on so long -
Sandy in Mooresville, NC - visiting in upstate NY (Gloversville) at the moment