Both techs have their pros and cons. Plasma just has more, especially with value for money, at the entry-mid level. Most people looking for TVs are on a budget, and a large proportion of their content is SD and sport. Most people have curtained rooms and view during dimmer ambient lighting, and most sit far from their TV. This is where plasma wins, at the entry level. For those that need 1080p on a tight budget and those that sit close to their TVs, for those who use their TV as a PC to do work on (non media/gaming), for those that have bright rooms - I would not recommend plasma.
Not sure, not a fan of LG. Sounds like the entry model though? In which case the Samsung PS43D450 43" HD Ready (1024x768 720p with rectangular pixels) will probably be better. R4,999 at Game.
You could also look at the PS51D450 51" HD Ready (1365x768 16:9), usually R5,999 - R6,500. Its pixel density is lower than the 43" model, but that won't matter once you're sitting 2m+ back.
If you like LG then try go to a proper AV shop and compare both in the test room under ideal conditions. Don't compare from the aisle at Game.