we got two sisters, Mitzy is like your neptune very affectionate and i often find her in bed with me or on my pillow, she constantly sits in my chest and throws herself back so she lies on her back to get her belly tickled, this goes on all day, she cries at me when i go to work and when i come home. she cries when i go to bed, and when i get up....sound familiar.
well Daisy is totally oposite, although she has become really affectionate over the past couple of days, (i think she is coming into heat) i cant pick her up, i cant give her the same cuddles, she wont really sit on my lap, unless mitzy is there, but they play together all day long, i find them snuggled in their little house when i come into the living room, they eat together and poo together,
my advice is, get another as soon as you can so they can bond whilst they are young, and it would be great if you could get a sibling, you can compare them as they grow, no cat is alike they all have their own personalities. Especially as your at work all day, afterall you dont want neptune to get too bored and start ripping your furniture up.