Hi. I've been mewing and trying to have oral posture for around two and half years now. I have seen some gradual improvements to my side profile, but the most recognisable difference is probably the length of my midface has shortened judging from the photos I have kept on my phone. I have measured my intermolar width and it is just over 40mm, which I am very happy with (didn't record the measurement before I started doing proper oral posture). When you get to the front of my palate however, it narrows It's like a gothic-shaped arch. I think the reason why this is, is because around five years ago I had extractions, which, I don't know why I agreed to it because my teeth were straight and fine, and the only faulty I could see was a slight gap between my two top incisors. My Orthodontist had said though if I kept my teeth the way they were there was a possibility of some irregularities (crowding would occur). I was kind of young back then and thought braces would make me attractive so I agreed to it.  I had four pre molars removed, two top, and two bottom, with braces to close the gaps. I think because of this I haven't been able to place the front of my tongue onto my palate. My tongue sort of curls up at the front when I suction, I am pretty sure the posterior third of my tongue is touching my palate still though. I think this is the reason why I haven't been able to get any expansion round the front of my palate, is because of my tongue being in this position.

I've tried many myobraces and my teeth do seem more aligned than before, and I think (only estimating) I have achieved 0.5-1mm expansion from a myobrace. Although, this isn't enough to be able to place the front part of my tongue into the correct position. Unfortunately where I live the Orthodontists do not believe and are not trained for palate expansion, so I think it is going to be a DIY job. My question is, what kind of palate expander should I get? I am stuck in-between an Active Plate and a Y-Plate Expander (unless any others are recommended). I have looked at a few videos on YouTube and most people seem to be favouring the Y-Plate. But, I've heard the Y-Plate can cause teeth tipping (credit to Apollo by the way he has gave me extremely helpful advice explaining to me the risks that come along to expanding with these devices). But if I avoid a certain screw, should it be less of a risk? As I have said, I mainly want the front of my palate expanding. If there is any device which focuses on this part of the palate. Although, to have expansion at the rear of my mouth at the same time would be just as good. 

Would be extremely grateful if anyone could give me any advice. Thank you!

Forgot to add. I plan on buying the expander from www.bracesshop.net.

I have also attached below, not the best way to measure your IMW I know, a look to how my palate looks by biting down on a piece of spare cardboard.