not one school, bubbley. dd1 is 10 and in her fifth school, ds1 and dd2 are in their second schools but about 4th or 5th if you count nursery/ pre-school.
if you are expecting 'education' to mean 1-1 time with an adult (this seems to be the rationale?) then of course, no educational establishment is going to match up tbh. you're quite right. that level of attention is unattainable and actually i believe not particularly desirable. i'm interested that they are small schools (with presumably small school sizes) that aren't acceptable - presumably this would mean more 1-1 time, not less? (if this is your criteria?)
i'm curious. dd2 had statemented 1-1 support for yr r because of her cp. you seem to be suggesting that a TA in the class purely to support an sn child/ sn children is a bad thing, whereas i see it as enabling not just my daughter, but a group of similarly able (yes, able) children to extend their learning by moving at a faster pace. it's actually easier for a teacher to extend the more able children with dd2 in the class. 
i'm sort of resenting the implication that all the sn kids must have learning disabilities which preclude them from working at the same or higher level than their clasmates tbh.
that said, we have occasionally requested that TA support be minimised as we felt that she was becoming too reliant on adult company (note - company not support - she would talk about going to school in terms of going to see x and y (the support staff) and not her peer group friends.
anyhoo, there has only been one school so far that was not suitable for my children (the headteacher advised me not to send them to her school - i can already see you thinking 'oh, that's like us' but in this case the school was an inner city fresh into special measures, with a transitory population and a plan to implement a huge behavioural transition plan over the next two years. in their case the priority for the school was to re-establish discipline and work with the community to provide early parenting support to raise entry ability.) in terms of the ability and social capabilities of the peer group she told us to look elsewhere, and come back in two or three years, when she felt the environment would be more suitable.
but the next school we looked at was fine.
i'm really struggling to believe that any teacher, or ht, told you that your 4yo would be bored at school tbh. you might have inferred that from looking at the level of work in the nc at that point, but in our case suitable differentiation has been in place.
but like i said - i'm actually quite pro-he. i'm just curious what your rationale actually is. apologies if it isn't 'my kid is too clever' but that was the implication i picked up. why do you want to he? (genuinely interested)