Wide angle lens options for FX

I know I know...another "which wide angle lens do I buy?" question but I have a question with regards to what I plan on shooting - I have a D700 and 24-70 2.8, 70-200 2.8, 150 Sigma Macro OS and 50 1.4G.  I would really like to get the 14-24 as I plan on doing some real estate stuff, interiors, etc I also like doing landscapes/seascapes where I shoot into sun a lot at the moment using the 24-70.  I have heard the 14-24 is a no-go when shooting onto the sun due to the flare this lens produces.  I really would rather the 14-24 over the 16-35, should I consider getting the 14-24 and another wide prime for when shooting into the sun?  I use the 24-70 at 24mm quite a bit and should probably look at the 24mm 1.4 also but I just cant afford this as well as an ultra-wide lens at the moment and I am more focused on getting an ultra-wide lens at this stage.  any recommendations much appreciated, cheers.