Wheel advice please

Excuse my ignorance, but what are the issues with light riders and stiff wheels? (not a problem I have to worry about personally!)

OP, do you want brand new or are you happy with used gear? If the latter, a nice pair of Bora Ones is in budget, plus some nice tyres.

Yeah, sure...28's on 11mm rims with no issues. Santa Claus is real too.

I love the passive aggressiveness of, "Of course, road biking is what injured mountain bikers do"!!!

I'd head down to a local bike shop / wheel builder.  Have a chat with them and they'll sort you out.  You may end up with something "lacking in bling", but a made to measure wheel should outperform & outlast a factory built wheel.  You could well end up with the dull looking open pro's on a rather nice set of ultegra hoops...or something from DT Swiss and still have £500 left to spend on tyres, tubes, beer & curry.  I've just reclaimed the handbuilt wheels from my son, as my factory built wheels from a well known brand are irreparable and spares spokes are unavailable.  They are just nicer to ride on and feel every bit as fast.

I've been running 28mm conti gp 4000s all spring/summer on fulcrum quattros 17mm internal width. Have noticed no issues with grip or squirm. If anything this is improved over 25mm. I've ridden long sportives, chain gangs and Sunday Club runs down the dirtiest tiny lanes you can find come rain or shine. 

I've also used them at range of psi as I started spring at just shy of 100kg now weigh 85kg am 6.3 tall. Started off at 90 front 110 rear now run 70 front and 95 rear.

"Anyone telling you that a 28mm tyre on such a rim (as you've mentioned) will 'balloon' or cause squirming/lack of traction is frankly talking bollocks"

I didn't write about "squirming/lack of traction". I wrote about cornering grip. A ballooned tire does affect corning grip as sidewall intergrity diminshes causing uneccesary body roll. (see image) And, yes, an underinflated tire would cause this too, but that's not the subject matter.

Lastly, OP take a 28mm tire/tube to an LBS selling a 17mm ID rim. Ask to mount and inflate the tire/tube. See for yourself the ballooning (incandescent light bulb) effect after inflation then decide for yourself the rim size you desire.

I'm a little heavier than you (70kg) and really rate the Mavic 125th Anniv Ksyriums. Braking in the wet with Exalith is almost as good as the discs on my winter bike. IIRC they weigh in at around 1350g for the pair.

Another recommendation of Hunt wheels from me. 

I would get the shimano they are just fine in all respects

What super python says above is correct. The amount of bullshit around tyre and rim width in the road bike world is amazing. Have you cornered so hard on a MTB that the tyre deformed and came off the rim? All MTB wheel tyre combos look like massive light bulbs. I rode around for 3 yrs on 2.5in wide balloon tyres on old school narrow 26in MTB wheels on tarmac without any problems or even a puncture. Sometimes I'd pump them to 80psi and often ride them at 30psi.

I'd go Shimano. The hubs are great (and very easy to work on) and the rims are very light indeed. Wait for the wider ones if you can.

EDIT - At your weight you could look at Extralite. The Hyperclinch SP are around your price range and 1240g. Essentially hand built, wide rims and a sensible spoke count for the rim for a light rider.

The current C24's are narrow width rims, OD = 20.8. This means the internal diameter (ID) cannot be wider than 17.8. I don't forsee the 2017 line being that much wider. Mounting a 28mm tire on a narrow rim would cause the sidewalls to balloon ( ) which negatively affects cornering grip and increase tire size. For example; a 28 on a C24 would measure close to 30/32. YouTube Mavic hub maintenance and hub bearing load set. It's a b*tch and why I ditched my Cosmics.

For your budget I would suggest looking into custom wheel builders. I did and most happy with being able to select my rim type, the size (ID, OD and H), hubs and spoke mfg.

Have a Google for Hunt wheels, they're very good.

Shimano have just updated their range of wheels and they are wider now, they should be appearing on the market this month if you can hang on.

The latest versions of the Mavics are wider, I'd have thought that with big tyres comfort would be OK.

Carbon rim braking is not going to be the best,  if that's a worry then the Hunt carbons aren't going to be so good.   The Hunt race aero is light and has an alloy brake track, much cheaper too.

For wide and light (and a bit different) how about HED Aredennes?: http://www.hedwheels.com/proddetail.asp?prod=ARDBlack