More agressive position and new wheels. Tips, please!

Handlebar height:
Give it a
Handlebar height:
Give it a go, but don’t necessarily expect benefits to outweigh any initial discomfort on the first day.
But this is only really relevant if you find you are riding on the drops for the majority of your ride. If you ride on the hoods a lot, I would suggest getting used to being in the drops first would make more sense than removing the spacers.
It does take a little while to get used to being a bit lower. When I was getting back into road cycling, I was (a little) fat and not very flexible and it took me quite a while before I was feeling properly comfortable in the drops – I even considered getting compact handlebars to reduce the distance. Now I comfortably ride really deep in the drops. My neck does not thank me on long rides though…

Wheels:
I would recommend looking at Mavic or Fulcrum wheels. You can usually get some good prices, and you won’t go far wrong. I had some Fulcrum Racing 5, which I have now put on my winter training bike. They’re great wheels for the money. The Mavics are tasty though.

I had a set of Pro Lite Comos which I did not like at all – they were super heavy and felt slow. This has put me off Pro Lites. I also had some handbuilt wheels laced to Ultegra hubs, and I really felt that the Ultegra hubs were a step below the Mavics I was running at the time.

HTH

Nope, but you will extend
Nope, but you will extend your reach, so you might find yourself moving forward on the saddle. When I was too low at the front I used to get a stiff neck or shoulder pain after a couple of hours. Try it, one spacer at a time and if it doesn’t work, put the spacer back.

Your cables are curved, and the outers take up the slack effectively, so when you move the end, the cable run remains the same, because the sum of the outers and distance between the stops is the same.

I assume you ride on the drops usually? Not much point dropping your front end if you don’t

There was a good article on Andy Schleck vs Wiggo a while back comparing TT position, and it made some good points about muscle activation angles. Essentially Andy’s muscles would lose power in Wiggo’s position, and would actually offset his aero gains and then some, so big changes in position may be beneficial or counter productive. If in doubt get a bike fit, and save up for the wheels later.

As for wheels, depends on budget. The new Ultegras get good reviews. I have RS20, 105, Ksyrium Elites and some other odds and ends, and the Ksyrium Elites are the best to ride. Other brands worth a look are Hope (their wheels are used in the Road Bike Party), American Classic, and Strada have the Velocity and some new rims which make up into wheelsets for the custom build crowd which are in that price range. Not heard anything good or bad about the Pro lites. Pretty much any decent wheel set will come in lighter and will improve your ride enjoyment. Obviously the more you can afford, the lower the rotational weight, the bigger the effect.

won’t give advice on wheels,
won’t give advice on wheels, but i think it is reasonably safe to lower your handlebar little by little, i would suggest going one spacer at a time (i know they are 5mm, but still) and keeping it that way for a couple of weeks before going further. Also try and be realistic about what sort of benefits such modifications give to you, i mean it’s all well and good having the handlebars a bit lower, but if this limits the power you can produce in the drops due to hamstring flexibility for example, than it’s obviously counter-effective.