The UE11s are cheaper than the A4s, the 64 equivalent - unless you are looking at a 64 with a lower driver count. Between the two quad driver options (UE11 and A4), there's no wrong option. Go for a quad though. Choose it based on colours or which name you lilke the best if you want. They both sound different to each other as they are tuned slightly differently... but to be honest, either is going to job better than you could imagine - and you'll only appreciate the subtle differences between the two if you are A/Bing them back and forth. Hey, you may even want to go with the Apex option if you believe that that offers some sort of advantage!
With regards to 64 though... I don't really know whats happening in the imminent future. I suspect the range is going to be refreshed with the Tia driver... as at NAMM, they announced the A4t. The A4 may become obsolete - in which case it may be worth going for that now before the A4t comes in, as I suspect the A4t will come with a price rise. I don't know for certain though. Maybe in you speak to Paul at CIEM he may be able to advise - but I suspect he hasn't had the pricing through yet. It would be unlike 64 to offer a blow out on the A4 model - they may even keep offering both the A4 and A4t models... I don't know. You may not even care about all the Tia driver stuff!