Nawhite's ideas are good, but somethings to look at/ research on each one.
1. CD ladder may be great for the situation, that you have a set time-frame for needing the money. However, the last time I checked CD rates through mint.com, my local credit union, and my online bank, all were lower than the interest rate I was getting on my 360 savings account. So no reason to lock up my money for less return. If you can find a CD that is higher, great!
2. I don't know much about, other than it may take a bit slower to get your money, than in a bank account. Research it first.
3. REIT's are very tax in-efficient. so to make it worthwhile, you'd want it in a tax-sheltered (retirement) account.
4. Yes, a Roth is a good idea, if you track exactly how much you're putting in. However, even in a conservative fund, if the market tanks (and you don't know when that will be), you might be at less than you started. If it was just for retirement, it wouldn't matter, because you would have time to ride it out. But if you're using it as a need in 4-5 years, that would be difficult. A money market would solve that problem, but I know vanguards prime money market account is returning less than my 360 account.
5. I haven't seen that to be true, but maybe in nawhite's area it is. Also, I know people on here have used ally before, I just don't have any experience with them.
But yes, by all means shop around to see if you can get better cd rates, I just haven't seen any recently that beat an online bank savings account. And I'm of the mindset that watchmaker said, and like I explained above in #4. Since you have a set-time period, you may want to stick to something a bit more guaranteed, if it is truly a "must have." But maybe you want to be a bit more risky than us. It'll all come down to personal choice.