You already have a bunch of great answers, but I'd like to put my 2cent in too.
About your comment first comment regarding pricing. Lake Nona is booming. So, you will be hard pressed to find many REO/foreclosures left coming on the market and when you do, they will be very competitive. So, that usually means list price or over and cash buyers. Ofcourse a good agent can only do so much when it comes to this since the seller (bank/Fannie) chooses the offers with the highest probability of a sure closing. In other words, cash is king in this segment. The best time to enter that market was between '09 - '11 when REO's were coming to the market often. Most of those investors were investing for cash flow.
Now, it is a different story. My investor clients, last year began to invest in Lake Nona focused on appreciation and less on cash flow. They are using equity from previously purchased properties or using new mortgages to leverage their buying power.
So, you should be aware that this market has changed from what many others will tell you. The days of distressed property bargains are gone.
That does not mean that prices are too high. In fact, it means many smart investors are taking advantage of low rates to invest in growth areas. Lake Nona is clearly set for growth!
Assuming you want to invest in the way I explained above, you should expect to focus your searching on new properties or newer. (New saves management $ because of warranty) You should also focus on location within Lake Nona. Just because you can buy more sqft out in Moss Park (east of Nona) does not make it a worthwhile investment. You need to compare rental rates by location to be certain what your property will provide in rental income.
One other thing to mention regarding your question about property type (townhome, single family, condo) be aware that there is a new leasing community already built and others on the way. These are geared towards high/middle end tenants that want condo type leasing. So, in my opinion you should steer clear of the condo/small townhome option because of competition. However, if you purchase at the right price it is possible that these nearby rentals could support a higher price, but timing is key since you wouldn't want your property sitting empty because of vacant competition.
Sorry for the long answer, but many other investors have similar questions about lake Nona and I hope my explanation helps you and them as well.
You can visit the GalleonProperties.com website through the link below and use the Investor Search Tool. There you can search all MLS listings by map and compare current rental rates around each listing!
Please visit the blog on Trulia or GalleonProperties.com too. There you will find a few articles about investing in real estate and several of my past Q&A's with investors like you.
Best of luck on your investment,