The vibrations could just be a balancing problem, check both wheels are balanced up front.
It might be a partly balding tire (Check inside edges of the tire as these tend to get worn away quickly if the cars tracking is off).
It may also be that you need new bushes on your wishbones (Lower Arm suspension) which means changing the complete wishbone and best to do both sides. I think a wishbone costs around £60 + VAT & P&P (But I'm only guessing here best to phone up and ask (01484 86533)), from Alternative Auto's (Usually a good bit cheaper than Fiat) for OE ones and cheaper non OE versions are available from eBay if you can do with aftermarket ones (Roughly £30 + P&P).
You might just need the anti roll bar links (drop links) replaced as they might be worn (I think about £12 + VAT each for the bar and bush).
And again track rod ends may need replaced (£18 + VAT each) while you are tidying up the suspension.
There are other possibilities as unfortunately there is a fair few things that can go wrong.
Some items are cheaper on eBay but be wary of quality, some stuff is genuinely good but some is rubbish. When I replaced these parts I got OE parts as they are
supposed to last longer and bought them of Alternative Auto's to save on Fiat's prices even though AA's postage is a little steep to where I live (non UK Mainland resident).
If you have enough cash to spare it is always recommended to get all 3 things replaced on each side at the same time to save on possible new problems occurring quickly afterwards.
Some people will say that some of these items are not likely to be the cause but I noticed a difference when I changed mine.
But my main piece of advice is to check both the balancing and tire wear/tracking. Then if this isn't the problem, ask a mechanic to have a quick look at the bushes on your suspension arms and links as he should be able to see problems and he should do this for free.
The conking out problem sounds like fuelling but I don't know much on that. Does she idle ok? If not then there may be a problem with the idle control valve or a problem with the throttle not opening up fully which could be a sensor problem (water temp etc.). There are many how too guides on the
http://www.fccuk.org/forum/ and loads of the guys over there are really helpful, I would be lost without their help. Sometimes you get contradicting advice and doom and gloom possibilities about what is wrong because they have all had experiences but generally it is the more common problems that are the answer to most people’s queries. They will definitely help you out in all areas and are all sound people.