There arn't any true HD screen in Singapore...plasma or other wise. P or I There's a lot that claim to be but they are merely scaling to suit.
Actually... 1080i by definition isn't true HDTV, as the signal is interlaced from 2 540pixel images. 1080p is true HDTV, and you're right, they're not available in Singapore (or just about anywhere) yet.
You should also read up on 1080i interlacing methods, as some (about 50%) of the HDTV sets only use half of the 1080 lines that are transmitted in HD.
In a nutshell, a 1080i signal is transmitted in 2 parts, with 540 odd-numbered horizontal lines, followed by 540 even-numbered lines. The reason a lot of the HDTV's display only half the 1080 lines is that a lot of the manufactures only display the 540-line half-resolution fields sequentially and upconverting them to the native HDTV resolution (720, 768 or 1080 lines). The process is called 'bobbing' or interpolating.
The proper way to do it without any loss is to 'weave' the 2 signals together, but that takes a lot more CPU power, so costs more for the manufacturer.
Here's some stats (from 'The Perfect Vision' magazine):
All Samsung plasma and lcd displays do it properly, none of their rear pro Tv's do.
Just about all Pioneers do it properly.
All JVC's do it properly
All Hitachi's do it properly
All Toshiba's to it properly
Only 2 Sony TV's do it properly
None of the sharp TV's do it properly (LCD, Plasma or front projector)
So keep this in mind when buying a HDTV.
Also, consider that when Blu-ray or HD-DVD hit the mainstream, the only
way you will get them to display on your TV in HD is if you have a HDMI input... so you don't want your TV to be out of date in 12 months (it definitely will be if you buy EDTV!).
You might also want to look at rear projection TV. The picture quality is generally better than flat panel (most of the new RPTV's can do great blacks, with excellent colour definition), and the price is often cheaper!
Just my 10cents worth.