One more thing - if you've got time you can always rent the lenses of your dreams, pick the one that works the best and then invest the cash when you know which one worked best.
There are some good outfits like Lensrentals.com and Borrowlenses.com. I have used Lensrentals in the past with great success. They're awesome to deal with and have everything you need. The 50 and 35 prime lenses would be very cheap to rent.