Right now I am on initial Tier1 (G) 2 years visa and I have extension in Nov'2012. After extension I will be granted(

My Tier 1(G) is based on Employment and Self Employment both.
My question is in 2015 should I apply for 10 years settlement or 5 years of settlement for ILR?
Because 5 years settlement need tax documents/papers (not sure for 10 years), so that I can get prepared for tax documents from now.
Thanks.
Biswa