Once you hit the A12 at Ipswich its pretty much all single carriageway into Yarmouth, and the a12 round lowestoft can be a nightmare, as they are doing closures on the main bridge across the broads..... aswell as roadworks leaving it to taffic lights.
If your going down the A140 and cutting across that is equally as bad, alot of low speed limits, not more than 50mph for most the way, no dual cariageways and again on a Friday it will be a lil bit of a nightmare.
Oh and either route you take, look out for the large police presence on both those roads, both are renowned for bad accidents so there tends to be alot of speed camera vans lurking.
Hope this helps, and have a good weekend
