...If you look at the 2016 street view imagery, you'll see concrete columns and a few curved at the top styled casual replacement steel columns, but look at the street view imagery taken this year, and all the concrete columns have been replaced with the L shaped steel columns).Aside from those who would recognise the GSV image due to its locality, it is accurate to describe this streetscene of having a fairly typical UK streetlighting installation which can be found replicated in most places in the UK.
The new columns with the plain outreach comprises the most commonly used combination (and probably the most aesthetically displeasing, depending on which lantern is used). In my opinion, the best looking columns were the octagonal tapering design which were popular in the 80s. Any lantern would look good on them and they blended in with most streetscenes. I've not seen any of these installed recently though.
The curved top brackets you describe are most likely still available, but are probably more expensive to buy.
Interestingly, since the introduction of LED lanterns, the traditional 5% uplift on the outreach bracket, is seemingly obsolete by the need for the lantern to be perfectly horizontal to the road.
In the Stockport area, the 5m concrete columns which still survive are being casually resleeved to 6m with a bracket which has no uplift at all. Interestingly, the existing Beta 5 is refitted afterwards, although I suspect this is only a temporary fix until a possible LED programme gets under way.