Attaching 2 gates to concrete fence post

I'm looking at replacing the run of fencing between us and the neighbours.
They are parallel detached houses about 6 foot apart with the fence down the middle.
I'm going to be using slotted concrete posts with 6 inch concrete gravel boards.
The end post will have a gate either side. I'm a bit concerned as to how I'll be able to attach the wooden gates to the concrete.
Should I pre-drill the holes before I concrete the post in just in case?
Can you drill through the steel support inside the post? (I have an sds+ drill)
Should I attach a wooden post either side of the concrete one.
I'm ordering the posts from a local builders merchants, are there special end posts?

ask for the end posts. dont bother pre-drilling, it will ceratinly be in teh wrong place. the concrete can be drilled easily with an sds drill but can spall on the opposite side so be carful as you drill it. Most posts have 5 small bits of rebar in them running the length, 4 in each corner and one in the middle, so you should avoid it, but if you dont, you can usually get through it with some effort as its only thin.

your best bet would be to attach timber posts to them. let the conceret in the post holes go well off before trying to attach the gates as they do put a big load on the posts.

Thanks.
The other alternative I'm thinking about would be to start with one wooden fence post at the end instead of the concrete one, but that would make the fence slightly weaker.

Not really, if you get hold of a 4" or 6" post it will be very strong. And the constant opening closing of the gates might put a strain on a concrete post which could cause cracks over time.

If you can track down a decent oak post on ebay or something then even better.

Why not fit the gate hinges to your house wall, and just the catch to your post....

best support there is!