I’ve researched on Google and apparently 4-6 points and up to a £1000 fine seems most likely, or a driving disqualification of between 7-56 days.
Nope - it's a Band C offence - so 6 points or ban of 7-56 days.
Costs of around £85, fine around 1 week's relevant earnings and surcharge of 40% of that.
Is it also worth seeking legal representation in this case?
Not usually if you intend to plead guilty. The SJ is initially a desk-based process where you cannot attend. They may decide to sentence at 6 points or potentially refer the matter to court (for which you can attend) to consider a ban.
It's probably worth seeing what the SJ decides in the first instance - they may sentence at 6 points and the matter won't go further.