You're going the right way by not aiming for a stupid supersports that'll kill you with one mistake.
The CBR is good, reliable and a nicely balanced bike that you can get your toe down with.
Aprillia I'm assuming you're looking at a 2 stroke - these need careful maintenance or the engine will seize or go pop, etc. If you get a second hand one you need to be so careful as if they've been thrashed/neglected you could inherit some seriously expensive problems. They're faster and easy to de-restrict when you do your test but frankly they're barge-pole material for most people. If there's a new four stroke out then insurance will be high as they'll be quite stealable.
The YZF is supposedly the best one out there but frankly given the large extra cost I'd go for the CBR. You can get a nice '05 CBR. You will most likely drop the bike (most people do, what's embarrassing is when you do it in front of your ex girlfriend and she has to help you pick it up... the shame) so buying new is throwing away the cash.
In reality I think there's little to choose between the CBR and the YZF except that the latter looks like a big bike whereas the CBR looks like what it is - a little 125 dressed up. I'd have the CBR every time.
As for the move up to 250s. Kawasaki all the way. Again because you can get decent examples second hand. At this point it becomes an insurance issue. I don't know your age but for me at 25 any new bike will cost me one hell of a lot of money to insure to the point where it's not feasible. Again as it would be your first big bike, dropping is a possibility so I'd not go for brand new. There is the fact that the Honda is very well priced but I think the BHP is lower.
With your 33bhp licence you can also get a bigger bike and restrict it. Obviously insurance companies would puke at a CBR600RR but if you look for something nice and light (around the 150Kg mark) then you can get much better performance due to the lower weight. The other thing is that bigger bikes hold their value a bit better and when you derestrict it, you're already used to the handling, etc when you get the extra power so you can use it easier. If you're doing your test on a 125 then this is something to consider once you've got a 125 sorted.