If you go to keswick dont do the bash* and then a trail centre – in fact done go tot he lakes and do a trail centre – the bridleways from Grizedale are a notable exception
As noted on here going to the lakes and riding a trail centre is like going into a brothel for a kiss.
If you are staying South then my advice is
Something around Kentmere/Staveley to get a post ride nosh upa t awilfs – Anan bield/High Street/Garburn
Something around Grizedale
Something massively high like say Helvellyn
* Decent ride but better options are available and half of the bash is not worth doing IMHO