This is all rather speculative stuff guys.
Where do you really want to start from?
CVA-01?.....which CVA-01? Because upto '62 it was a 50,000ton CV design, when the defence minister questioned the artificial limit, and the whole process kicked off again.
OR shall we say the design submitted and approved in 1966?
Then the Defence Review killed off the long term future of the RN's conventional carrier fleet.
Assuming the latter, the projected airwing at this stage starts with the F4K Phantom II and S2 Buccaneer, as the decisions concerning the F4 where earlier.
This is the periode of the AFVG, but the French will withdraw by June 29 1967. It seems the whole anglo-french episode was doomed to failure anyway.
UK continued with its fallback position, the UKVG effort.
So presumably if the RN's carrier fleet has a future along with new ships like CVA-01, then the desire to replace the Buccaneer with a supersonic strike platform will change the UKVG effort.
This would certainly effect how things progress, since the compromises to make it a joint RN and RAF machine could seriously put off the Germans when their shown the UKVG in 25 Oct 1967. Their responce was less than enthusiastic as it was, how things would progress with a even more negative response is not clear.
Its even harder to see how the ACA effort with the F104 consortium is going to get started, since none of the members are going to be interested in a Navalised variant and are all looking for a replacement for the Starfighter. There could very well be no MCRA at all, and thus no Tornado.
Dassault however is now in a very strong position with the Mirage G, but its hardly going to go down well since it was developed as a purely french alternative to the AFVG for the MN. It would take the French political elite to force Dassault to make concessions to get the RN buying that and I don't see that happening considering the influence Dassault has with the French political class.
Now if we're talking of the earlier A1/D1 50,000ton design of 1962, then this is ideal for the BAC (Vickers) Type 583 and the HSA (Brough) P135. Except that time is running out, since once the Russians display their new large anti-ship missiles, the Sea Vixen is going to look utterly ineffective as a system and a replacement needed quickly.
Worse these UK aircraft are being offered with UK missiles and UK radar, none of which actualy exists, so the risks of delays and cost overruns is very large.
It helps to understand the underlying drivers for the F4 procurement is the idea they need a radar/missile combination on a supersonic platform as soon as possible to counter the percieved Russian capability. Its almost certainly why, when the Type 583 is offered again after the dropping of the P1154 that its rejected despit being a more attractive type than the F4. Simply because it could never be in service in time and had too much risk associated with it.
Thats why there is the offer to fit new AI pulse radar (possibly called AI.25) to the Sea Vixen in 1966 and new long ranged AAMs in 1968.
Soooo.....assuming you want an alternative that can be achieved in 1962, then I suggest the B.129/P.140 from Brough. A supersonic version of the Buccaneer offered in 1962 and 1964. Matched with a developed AI.23 and Radar Red Top for a ISD of 1968.
But if you want an alternative in '66 it has to be the HSA (Brough) Next Generation Tactical Aircraft concept P141. That seems quite achievable if your ISD is 1972 or later.