I wouldnt say its hard finding somewhere decent to live, but I think most of the london members would agree, finding the right place to live where you are comfortable always requires some preparation and patience.
With your living requirements you mentioned, I think you may need to dig a little deeper into your wallet to afford those luxuries when living in the capital.
Get on the net and do some research. Phone some agencies and get an idea for prices.
Now is a good time to get things moving.
Here is always a good place to ask, like your've done.
The Picadilly and Central lines are ideal, but then again, it depends on where you are located on these lines.
Good luck.