On the technical side -
SCART is not a problem as there converters from SCART to Component, etc.
PAL is in analog era - no worries if you don't plan to connect composite and s-video inputs to your TV.
All you need for your TV is HDMI, Conponent and VGA inputs - these will work anywhere in the world, all you need to care is that your TV can handle both 50Hz and 60Hz signals.
You can always buy 50Hz to 60Hz HDMI converter but these are not cheap.
Professional Panasonic, NEC and Pioneer plasmas all handle PAL and 50/60Hz signals. AFAIK, they will handle 240V 50Hz power, so no need in step down transformers.
There were also posts here on AVSForum from people taking consumer Pioneer 6010 plasmas to Russia and Israel and having no problems.
Is it worth it taking plasma to UK? AFAIK, prices in Europe are higher for flat panels, if you don't have to pay for shipping and insurance then you can take a panel with you. In the same time if there is a problem then you will have to pay for repairs yourself that might be costly. You have to ask yourself if the price difference between the States and UK worth the risk of bringing a panel with you?