This isn't actually about senegals as I have no experience at all with sennies (never even met one!), but I've been watching your threads and I wanted to give you my two cents on finding what you're looking for in a bird. Just some take it or leave it advice here, but hopefully it will be helpful!
I think it's awesome that you've done so much research looking for your perfect bird, but since your main quality is that it have a very strong relationship with you, I would worry less about the specifics of the bird type and start looking at actual birds themselves. As an example, Quakers are one of my favorite birds and the best buddy bird that I EVER had was a Quaker. You may have seen him around this forum--his name's Sammy and he lives with Allee and her other kiddos now because I moved to Honduras for a year and wasn't able to take him out of the country with me. Some Quakers are amazing like Sammy was, some drive me nuts--I like them all, but I don't count on them being a certain stereotype just because of the kind of bird they are. Each bird is SUCH an individual that it's crazy, so if what you want is one that is going to bond REALLY strongly with you, I would look for that quality in the individual bird rather than the type itself. The generalities of a species are just that: generalities and stereotypes. These are based on truth, but don't apply to every bird. If I were in your situation, I'd keep a very open mind on the kind of bird and start looking at individuals, analyzing their unique personality. We all have certain kinds of birds that we want, but if you make up your mind based on type of bird, you guarantee yourself a certain species but make a sacrifice: you have to be willing to take what you get. I have always wanted a rose breasted cockatoo, for example, and I am getting one next week. The breeder has told me a lot about her and she seems awesome, but I have accept that she will be the bird that she is, no matter what personality she comes with, because I am buying her from out of state. So I get my dream bird in type, but make the sacrifice of choosing an individual bird in person. She may bond instantly to me or she may hate me right out of the box--no way to tell. That's fine with me, but I can tell from your posts that having a bird who is your best bud is your main goal (since that seems to be what you're basing the bird type search on). So if I were you I would worry less about the individual species and start thinking about where you might be able to VISIT birds that are for sale or up for adoption to find one that you REALLY mesh with!
Anyhoo, not being critical or anything, I just don't want you to end up picking the perfect species then actually getting the bird and finding out it's the one out there who doesn't match all the stereotypes of the kind! Good luck in your bird search!!!