not totally clued up, so which is better option between the to ?
and more importantly... any billy bargains out there ?
As said already, not a case of one being better than the other, it's down to suitability.
If you need a desktop, go for the iMac with an amazing screen. If you prefer the laptop, go with the MacBook.
Then the question is which MacBook, theres a few.
Decide which you need, then next step is deciding which model suits you most. (Portability, speed, price)