Bit of local knowledge for you: Acton Lane via Newman's Green is not a very pleasant road to ride when the shoppers are rushing back and forward to Sudbury. It's quite a fast but narrow road, and it's scared me a few times - both in a car and on a bike. The A134 Sudbury 'bypass' (well, it was when it was built) isn't a pleasant ride either. I'd suggest carrying on through Acton to Waldingfield, down Valley Road to the 134, right and left onto Joe's Road then via Sacker's Green to Prospect Hill and rejoin your route.
Kedington Hill is fun either up or down, but I normally turn first left off the B1508 (another fast road with poor sightlines) up Chapel Hill. Not as steep as Spout Lane, but more pleasant.