The sb's are a fine option...and since in Flash photo, when it's not something like paparazzi work, you want control and consistency, they are GREAT flashes. One problem though, they are fairly old flashes and you get no warranty (and i think the price has gone up to fairly more than 75$...at least in fleabay).
The YN are a good option, great price, but big CATCH: chinese quality cntrol and then customer service are far from brilliant and they can be a real hassle!..it's a thing of luck or lack of it.
The metz 48 is a fine option...with manual control up to 1/128 of it's power...great build quality and quality control. i think that for your stated purposes this is one of the best options, but if you start using it off camera you will soon start looking at other units to complement it and get a more versatile and capable setup.
You could look into the Sigma 610 super too...
I'm assuming The Cardiff in your location is the england one...if you were in the states the lumopro is a mouthwatering flash (good QC and 2 year guarantee).
My advice would be to see the lighting in layers DVD, or the Zach Arias one light workshop DVD and then explore the different manual flashes you can buy...and also consider the usage..because when you start thinking about lighting gear the speedlights can get to the prize of studio strobes quite fast...
For the triggers check out the cactus V5...they are fine, have some great features...but have the chinese made and marketed issue (although the feedback on this particular item seems pretty good)...
I got the seculine Twin link wich are working fine because i needed them for a job and could not wait the v5..so i went to a phisical store and got me these.
good luck, you're about to enter another realm of buying addiction, hunting and gear comparing
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