Head mashed over wheel upgrade!

Don't buy deeper rims if you want lighter weight.

I'd get RS81 C24 - as suggested in last month's instalment of the never-ending Wheel Upgrade debate.

If you're keen to try tubeless then go for the (cheaper) Ultegra 6800 wheelset:

http://road.cc/content/review/126799-shimano-wh-6800-ultegra-wheels

And to answer your other question: no, you won't notice the extra weight.

In fairness, I wouldn't be that bothered by the difference in section between the C24 and C35. I've just replaced my RS81 C24's for a set of Bora 35s, and the Aero difference isn't really noticable, and will make much less difference than the extra weight under acceleration.

With regards your width question, Its hard to say. My new wheels are 25mm wide edge to edge and 19 internal, they're not quite as comfy as the Hedd Ardennes I've test riden, yet they allowed 70psi in the tyres, where as my corsa g+ need a bit more due to the soft side wall. They're both more comfy than my old c24's though, using 25mm GP4000s.

The RS81's in either C24 or C35 are both good wheelsets, but I foudn my C24's wore out quickly (6000km) if you use them through the winter, and they're not that stiff. I'm 12 stone and the flexed under acceleration/climbing out the saddle. 

Based on the hubs of my Bora's, if you can find a set of Fulcrum racing Zeros (Normal, not the nite version) with a discount, they should come in around your upper price range. The USB bearings are so silky smooth, the bike will just glide along. They're also light and well built and ceramic should prove durable and problem free for many miles. 

Enjoiy whichever upgrade you chose, I've been amazed at the difference wheels can make to a bike. And for that reason, keep youre eye out for a bombproof set of cheap wheels to thrash when its winter and everything is covered in grit/mud! 

She's wearing a pair of box rim 32 Spoke handbuilts now.
They look every bit as good, but I can feel the weight difference on the hills round my way. The Braccianos are undoubtedly better climbing wheels. The rear drive side spokes are tied together which improves rigidity (the old skool method was to solder them) so the weight difference stands out.

Prolite Bracciano A27 in silver temporarily borrowed from my Ti Audax bike to take this baby for its first run after reincarnation. They also come in black with white decals.

Buy whichever wheels make you want to ride the bike more. Being happy with your bike is more important than marginal gains if you’re not racing.

I’ve recently switched to wheels with an internal width of 17mm. Compared to my old wheels which where 15mm internal width, I can measure that my 25mm tyres now come up 1-2mm wider, but I can’t say I’ve noticed an improvement in comfort.

There shouldn’t be an enormous performance difference between any two hubs, providing they are in good working order. Any properly serviced hub shouldn’t consume more than about a watt of your total power; the difference between cheap hubs and expensive hubs is how well made they are, how long the bearings will last, and how serviceable they are, not how fast you will go.

If you weigh 88kg, saving 300g off the wheels is reducing the total weight you’re trying to raise up against gravity by less than 0.3% (that’s before even factoring in the weight of the rest of the bike). By far the most dominant factor in climbing is the body weight of the rider vs gravity. A 0.3% weight saving will have a similarly small impact on you speed when climbing.

I have the Cero AR30 and Fulcrum Racing 3 wheel sets, and prefer the Fulcrums. Couldn't tell you why but they just feel like they roll and ride nicer. I thought it might be tyres and so switched to 25s on both but the Fulcrums still felt better. 

I used the AR30s over winter and had no problems so build seems good. Fulcrums went on when the temperatures went up.

Take the ceros and zipps  (discontinued anyway) off the list, add RS 81 c24 if you are worried about the weight of the 35s,  add Kysirium Elites, then it's a decent list to start with. 

If you do a lot of actual climbing the a lighter wheelset will feel better... You do however need to make sure they are laterally stiff, as there's no benefit in light wheels if the rims rub whenever you go upwards.

I'll now roll out my usual recommendation of Pro Lite Braccianos. I'm about your weight, but more muscle than podge. I have two pairs of Braccianos and I love them.

From your list, I'd go with Campag/Fulcrum

Rim width can affect comfort as it allows larger tyres and makes narrower tyres feel a bit comfier... But it's a marginal rather than massive factor in on-bike comfort