Hello and welcome Liam !
I think Peter has already summed it up very well, but I will add some comments of my own.
I do not own an Alnico II Mule, but do own a set of Alnico II 'Stormy Mondays' and a set of Alnico IV 'Mules'. I have swapped the pickups between an S.G. and a Les Paul, therefore my comments are based on my observations during these experiments and visualising your equipment.
(I often play through a Laney LH50R 50W Head, so we have further common ground).
I found the Alnico II magnet seems to prefer a lighter bodied guitar such as yours. It is just so open, detailed yet smooth, due to it's efficient yet gentle strength of magnetic field . The gentle / open focus of an Alnico II is so sweet and restful after the harder attack of an Alnico V.
I also found that the slightly 'hotter' wind of a Mule pickup creamier and more mid focused than a more 60's soul/blues type Stormy Monday.
My conclusion from all this is that with the open, less focused and 'breathing' quality of an Alnico II magnet - combined with the slightly hotter, creamier (yet still very sweet) quality of a 'Mule', you should have a winning combination for your needs.
Whilst I prefer to buy calibrated sets, money does not grow on trees - and so if you already spend most of your playing time on the neck pickup, you have already covered most of your needs, whilst (as Peter rightly said) discovering what tonal characteristic you might like for the bridge at a later date.
As a matched set user, I am predudiced in that I would use another 'Mule' in the bridge, albeit perhaps an Alnico IV to really 'focus' the tone more into the upper mids in that position. My only concern might be that the difference in power output may mean a volume jump between the two. Ask Tim on that one, as a second Alnico II might be prefered.
In any case, Tim never makes a 'bad' pickup and gives very accurate advice. I am therefore sure that you will enjoy your BKP and become as addicted as the rest of us.
The thing I most like about the BKP 'Vintage' range is that if you can appreciate slow sweet playing (like Larry Carlton) - you will find the hauntingly sweet sound of your Mule will make you hang on the notes more; therefore playing less and just enjoying every detail as the melody just drifts out from under your fingers. I know the BKPs made my Gibsons come alive and show thier true identity after being muffled for years behind sets of standard Gibson pickups.
Enjoy and Practice, practice, practice !
Regards,
Derek. :D
