This has always been a popular topic. Personally I've not got the hang of it but the brief encounters I've had were a pleasurable albeit painful encounter. Lots of lubricant, the patience of the one giving it and the right angle does the trick, so I'm told. This coupled with starting off small and then going to bigger "objects" is the way to go for sheer ecstasy.
But, where in this part of the world do you get this?
Unfortunately there are 2 broad categories of ladyboys - those that have a dick and those that don't. Your pre-op and post-op respectively. In Singapore, as in most parts of South East Asia, they work side by side in the bars and lanes of the sleazier districts. So, you've got to go up to them and ask directly - if you're going to be shy it's your loss because it's only the minority that can perform this task. Don't forget, the hormones that the ladyboys take are an erection's worst enemy. Some ladyboys who specialise in this niche would lay off hormones for weeks in order to fulfil their customer's expectations.
Another way around this is to look at sites like www.vicesisters.com . Those that do this service would sometimes provide photographs as proof of their abilities. Take note that the asking price for being active i.e. the ability to have a decent erection and penetrate you, is normally higher.
It's tiring work.