As you will see it’s a ‘very user friendly’ place, the people on this forum are very knowledgeable, and there is representation in UK, US, as well many other countries.
With a little more info on location I'm sure there is someone who's 'been there, done that' and will be able to help you...
Actually, I was at a tool store this past weekend and noticed a Bosch tool with a 5" or 6"velcro plate that bragged a 3/16 (I think) orbit and opperation from 4,500-12,000. Those speeds are fine, when polishing, I'd rarely go below setting 5 on my PC (maybe 5500 opm) If I recall correctly, that orbit size is similar to the porter cable's. It was ~$90. The bad thing about not getting a Porter Cable tool is that it isn't a Porter Cable. The counterweight can't be changed to my knowledge and it really doesn't seem like such a maintaniance friendly tool. There is also a bosch model which apparently will orbit and/or rotate. Seems like a killer machine, but it is also expensive.
I can't recommend one as I haven't got one myself, but have you looked at the other models mentioned above??
I would suggest finding out what models are available in your country first. Then provide weblinks so experienced Random Orbital users can then say either, 'that looks ok', or 'don't even think about using that'.
Try to narrow it down first to just a few models, but at the end of the day the decision will have to be yours.