20k...Assuming I want something that is low risk, I would invest
it all in Suntec Reit. At $1.06, it gives around 6% yield. SUntec
Reit is also projected to rise to around $1.20 next year. Although
capital gain not much, 6% yield is tempting.
Prime Reit only gives a paltry yield of 5.1% at 99cents. Capital
gain isnt there as there is not much space or reason for share
price to go up. But Prime Reit is considered more stable I
guess.
If you want something for high capital gain, I suggest buying penny
stocks. 
Currently, I dont think there are any penny stocks that has the
potential to double its price....